The Incense and Korach's Dispute
In the story of Korach and his rebellion, which our portion focuses on, the Ketoret (Incense) plays a central role. Our parasha includes two narratives in which the Incense features in a significant way:
First, in Chapter 16, Korach and his company gather against Moshe and Aharon, claiming that (v. 3) "The whole congregation – all of them are holy, with God in their midst; why, then, do you hold yourselves above the company of God?" In response, Moshe proposes a test to identify those who are chosen by God, to be conducted by means of offering incense (vv. 6-7):
This shall you do: take for yourselves censers – Korach and all of his company — and make fire in them, and place incense upon them before God tomorrow; and the man whom God will choose, he is the holy one.
Korach and his cohorts agree to this test. Two hundred and fifty men, along with Aharon, take censers and offer incense. Later, God's glory is revealed and the sinners are punished: Korach, Datan and Aviram are swallowed into the earth, while the two hundred and fifty who offer the incense are consumed in a fire that emanates from God.
Secondly, in chapter 17, after the death of Korach and his company, Benei Yisrael (the Israelites) gather against Moshe and Aharon, claiming, "You have put God's people to death" (v. 6). As a result, a plague breaks out among the people, and Moshe commands Aharon (v. 11):
Take the censer and put fire from atop the Altar in it, and place incense [there], and go quickly to the congregation and make atonement for them, for wrath has emerged from before God; the plague has begun.
Aharon carries out Moshe's command (vv. 12-13):
Aharon took, as Moshe had spoken, and he ran into the midst of the congregation, and behold – the plague had begun among the people. And he put the Incense and made atonement for the people. And he stood between the dead and the living, and the plague was stopped.
The contrast in the effects of the Incense in these two stories is puzzling. Why is it specifically the offering of incense that proves who is chosen by God, and why is it once again the Incense that stops the plague? Is the offering of incense chosen arbitrarily, as one of the priestly tasks in the Mishkan (Tabernacle)? How is it that the same incense that kills 250 men serves later to atone for the people and save them from death? What is so special about the Incense?
A. Incense Altar – Appendix to the Temple Vessels
Going back to Sefer Shemot, we recall that the commands concerning the Mishkan's vessels and structure are conveyed in Parashat Teruma. In the following parasha, Tetzavveh, we find the details of the garments and sanctification of the kohanim (priests). Towards the end of Parashat Tetzavveh, we find a general summary of the idea of the Mishkan (Shemot 29:43-46):
I shall meet there with Benei Yisrael, and it shall be sanctified through My glory. And I shall sanctify the Tent of Meeting and the Altar, and Aharon and his sons shall I sanctify, to minister to Me. And I shall dwell among Benei Yisrael, and I shall be their God. And they shall know that I am Lord their God, Who brought them out of the land of Egypt so that I may dwell among them; I am Lord their God.
This unit opens (25:8) with the general introduction, "Let them make Me a Sanctuary, that I may dwell in their midst." It continues with a list of every part of the Mishkan and its vessels that must be made, concluding with, "And I shall dwell among Benei Yisrael, and I shall be their God." Seemingly, this unit contains everything that has to do with the Mishkan. However, most surprisingly, following this ceremonial conclusion, there follow a few miscellaneous laws related to the Mishkan, the first of which concerns the Incense Altar (30:1-10, the final paragraph of Parashat Tetzavveh). Thereafter (in Parashat Ki Tissa), we find commands concerning the half-shekel (ibid., vv. 11-16), the Kiyyor (Laver) (vv. 17-21), preparation of the oil for anointing (vv. 22-33), preparation of the Incense (vv. 34-38), the appointment of Betzalel to build the vessels (32:1-11), and the requirement to stop working for Shabbat (32:12-17). These commands are not followed by another general concluding verse. Why does the Torah leave some of the laws relating to the Mishkan out of the unit that is devoted to this subject?
For the purposes of our discussion, we shall limit ourselves to the command to build the Incense Altar. Why does this command not appear in Parashat Teruma, among all the other vessels? Why is it removed from its natural place?
The first answer that we might propose is that the Incense Altar is not all that important and the Mishkan is complete even without it. The essential objective in building the Mishkan is that God can "dwell amongst Benei Yisrael," as stated explicitly in the summarizing verses, and the Incense Altar does not contribute in any way towards this end. It complements the Mishkan, but is not essential to it.
This hypothesis is strengthened in light of another vessel that is mentioned only after the unit on the Mishkan and all of its vessels is complete: the Kiyyor. The Kiyyor has no importance in its own right; it is meant simply for the kohanim to wash before entering the Sanctuary. While this vessel is unquestionably needed in the Mishkan, it is clearly of secondary importance. Is the Incense Altar similar in this regard? Is it likewise an auxiliary to the Mishkan and its service, with no inherent value in its own right?
Indeed, some of the commentators adopt this view. According to the Seforno (on Shemot 30:1), the Incense Altar is not mentioned along with the other vessels because it does not serve to bring the Divine Presence to rest there. Rather,
this matter of the [Incense] Altar is to give honor to the blessed God after He comes [to the Mishkan], such that He will accept with favor His nation's service of the morning and evening sacrifices.
In other words, while the Incense Altar gives honor to God, it does not play any role in actually bringing the Divine Presence to rest in the Mishkan.
According to the Rambam (Moreh Ha-nvukhim III:45), the Incense is meant to offset the strong odors emanating from the slaughter and burning of meat. According to this view, once again, the Incense is not an integral part of the Mishkan service; it is of secondary importance, and it is for this reason that the Incense Altar is mentioned after all of the service of the Mishkan is concluded, as an appendix.
Some contemporary scholars have raised the possibility that the Incense serves as a screen separating between the Divine Presence and the people, who require protection from such revelation. Chapters 25-29 list all of the vessels of the Mishkan which have the purpose of bringing the Divine Presence into the Mishkan, as the Torah indicates in its summary: "And I shall dwell amongst Benei Yisrael." However, since mortals cannot withstand such a revelation, there is a need for something that will shield them from its intensity and allow them to exist in proximity to it; this is the function of the Incense. Burning the Incense creates a screen of smoke that separates man from the Divine Presence. Therefore, while the vessels of the Mishkan are meant to bring the Divine Presence to dwell in it, the Incense has, as it were, the opposite function: to diminish the intensity of the revelation. Hence, it is clear that the Incense Altar is indeed of secondary importance (and perhaps even the opposite intent of all the other vessels); therefore, the command to build it appears separately as an appendix, after all of the other vessels have been listed.
According to the above three approaches, the command to build the Incense Altar is removed from the rest of the commands related to the Mishkan because the offering of the Incense is a service of lesser importance. It is not the main service of the Mishkan; it is not part of the service that brings the Divine Presence to rest there. According to the third interpretation, its role may even be the opposite – to diminish the intensity of the Divine revelation.
B. Is the Incense Really of Lesser Importance?
While this concept seems to make sense from the point of view of the textual position of the Incense Altar outside and separate from the main commands concerning the vessels of the Mishkan, a closer examination of the unit in question, along with some others that mention the Incense, offers a different picture.
Let us first review the command to build the Incense Altar (Shemot 30:1, 3, 6-10):
And you shall make an altar for the burning of incense; you shall make it of acacia…
And you shall cover it with pure gold –its top and its sides all around and its horns, and you shall make it a rim of gold all around…
And you shall place it in front of the Veil that is by the Ark of the Testimony, before the Covering that it upon the Testimony, where I will meet with you. And Aharon shall burn sweet incense upon it; every morning, when he prepares the lamps, he shall burn incense upon it. And when Aharon lights the lamps at twilight he shall burn incense upon it – a perpetual incense before God for your generations. You shall offer no strange incense upon it, nor a burnt-offering, nor a meal-offering; nor shall you pour a drink-offering upon it. And Aharon shall perform atonement upon its horns once each year, using the blood of the sin-offering of atonement; once a year shall he make atonement upon it for your generations; it is holy of holies to God.
Several details stand out in this unit:
1. The Incense Altar is overlaid with gold, like all of the internal vessels of the Mishkan, and in contrast to the Sacrificial Altar and the Kiyyor, which are made of copper.
2. The Incense Altar stands in the Sanctuary, alongside the Table and the Menora (Candelabrum).
The importance of its location inside the Sanctuary is further emphasized in light of the fact that the Torah does not specify the location of each of the other vessels as part of the commands to fashion them. Their positioning is described only in the command to make the Veil (26:33-36):
And you shall hang the Veil under the clasps, that you may bring in there – inside the Veil – the Ark of Testimony, with the Veil a division for you between the Sanctuary and the Holy of Holies. And you shall place the covering upon the Ark of Testimony in the Holy of Holies. And you shall place the Table outside the Veil, and the Menora facing the Table on the southern side of the Mishkan; and you shall place the Table on the northern side.
In contrast, as noted, the Torah notes the location of the Incense Altar right away as part of the command to build it. One could perhaps argue that this is because the command to build the Incense Altar comes after the command concerning the Veil and the specification of the locations of the other vessels, but still, this presentation seems to indicate the importance of the location of the Incense Altar as an integral aspect of its essence.
Indeed, in many places in the Torah, as in the above paragraph, the Table and the Menora are described as standing "outside the Veil" – i.e., there is an emphasis on the fact that they are not inside the Holy of Holies, but rather outside of it. The Incense Altar, on the other hand, is described as standing "before the Veil." Of course, the reference is really to the same place: the Incense Altar stands in the Sanctuary, along with the Table and the Menora, and not in the Holy of Holies. Nevertheless, there is significance to the expression that the Torah uses: the Table and the Menora are "outside the Veil," while the Incense Altar stands "before the Veil."
3. In the command to the build the Incense Altar, the Torah does not suffice with a brief description of the location – "before the Veil," but elaborates: "And you shall place it before the Veil that is by the Ark of Testimony, before the covering that is upon the Testimony, where I shall meet with you."
Two details are emphasized here: the Ark and God's Presence. The location of the Incense Altar is specified in relation to the Ark, in what seems to be more than a technical description of which space it should occupy; it is also a hint to the close connection between it and the Ark. In addition, the verses emphasize – three times – God's Presence. Admittedly, God's Presence is manifest from atop the Ark, but the Torah chooses to emphasize this specifically within the command to build the Incense Altar. Therefore, it seems that there is some special connection between the Incense Altar and the manifestation of God's Presence upon the Ark.
4. The Incense Altar is the only vessel concerning which Moshe is told, already as part of the command to build it, that atonement must be made for it once each year. There are only two vessels that bear this command: the Ark and the Incense Altar. A vessel that requires a yearly ritual of atonement cannot be regarded as something of secondary importance in the Mishkan service, and once again we note the significant connection between the Ark and the Incense Altar.
5. At the end of the passage of the Incense Altar, we read: "it is holy of holies to God." Even the Ark itself is not described in this way, and this final proof leaves no doubt as to the importance of the Incense Altar.
C. The Importance of the Incense
The command to build the Incense Altar is to be found in Shemot 30, and at the end of that chapter (vv. 34-38), Moshe is commanded concerning the preparation of the Incense itself:
God said to Moshe: "Take for yourself sweet spices – storax and onycha and galbanum — sweet spices with pure frankincense, in equal quantities. And you shall make of it a perfumed incense, in the manner of a perfumer, with salt, pure and holy. And you shall beat some of it fine, and you shall place it before the Testimony in the Tent of Meeting where I will meet with you; it shall be holy of holies for you. And the Incense which you shall make - you shall not make it according to this composition for yourselves; it shall be holy for you to God. Any person who makes [incense] like it, to enjoy its scent, shall be cut off from his people.
We see that the Torah goes to great lengths to emphasize the Incense's holiness: "a perfumed incense… pure and holy… holy of holies for you… it shall be holy for you to God."
Furthermore, just as in the command to build the Incense Altar, the preparation of the Incense, too, emphasizes its location in terms of the Ark: "before the Testimony in the Tent of Meeting, where I will meet with you."
In Tanakh we find three stories of people who offer incense and come to harm as a result:
1. Nadav and Avihu (Vayikra 10:1-2):
And Nadav and Avihu, Aharon's sons, each took his censer, and they put fire in them, and they placed incense upon it and offered a strange fire before God, which He had not commanded them. And a fire emanated from before God and it consumed them, and they died before God.
2. The 250 princes in Parashat Korach (Bamidbar 16:35):
And a fire emanated from God and it consumed the two hundred and fifty men who were offering incense.
3. King Uzziyyahu (II Divrei Ha-yamim 26:16-21):
But as he grew stronger, his heart grew proud to the point of corruption, and he transgressed against Lord his God, and he came to God's Sanctuary to burn incense upon the Incense Altar. And Azaryahu the Kohen came in after him, and eighty kohanim to God – men of valor – were with him. And they faced Uzziyyahu, the king, and they said to him: "It is not for you, Uzziyyahu, to offer incense to God, but rather for the kohanim, sons of Aharon, who are consecrated to offer incense; go out of the Sanctuary, for you have transgressed, for it shall not be to your honor, from Lord God." And Uzziyyahu grew angry, and he had a censer for burning incense in his hand, and while he was angry at the kohanim, tzara'at broke out on his forehead before the kohanim in God's House, beside the Incense Altar. And Azaryahu the Chief Kohen and all of the kohanim looked at him, and behold – he was afflicted with tzara'at on his forehead, and they took him out quickly from there, and he too hastened to leave, for God had smitten him. And King Uzziyyahu remained afflicted with tzara'at to the day of his death, and he dwelled in the house of separation, as a metzora, for he was cut off from God's House.
All three narratives depict attempts by different people to offer incense, each case ending in death. From these stories it is clear that offering the Incense is not a minor ritual, but rather a very significant part of the Temple service. Therefore, its performance by an unworthy person, or in an unworthy manner, is dangerous.
The other vessels of the Mishkan do not share this quality. We find no instance of someone dying because he attempted to light the Menora or to place the showbread on the Table. There is only one other vessel that has the same sort of effect – the Ark. In I Shmuel we read of the war between Benei Yisrael and the Pelishtim, during the course of which the Ark of God is seized. For as long as the Pelishtim keep it, it causes severe plagues, until eventually they decide to return it. Even when the Ark is returned and the nation rejoices and offers sacrifices, it brings death (6:19-20):
And He smote the men of Beit Shemesh, for they had looked into the Ark of God, and He smote of the people fifty thousand and seventy men, and the people mourned because God had struck the people with a great slaughter. And the people of Beit Shemesh said, "Who can stand before this holy Lord God, and to whom shall it go up from us?"
A similar episode is recorded in II Shmuel, where David brings the Ark of God into the City of David (6:6-7):
And they came as far as the threshing-floor of Nakhon, and Uzza stretched out to the Ark of God and he grasped it, for the oxen shook. But God's anger burned against Uzza, and God struck him there for his error, and he died there by the Ark of God.
In both instances it is clear that the people who die have good intentions: the people of Beit Shemesh rejoice over the Ark's return from the Pelishtim, and they treat it with respect. Uzza stretches out his hand to steady the Ark and prevent its fall. Hence, it would seem that their death is not a punishment, but rather the result of the intense holiness. A person who draws too close to such holiness will be harmed, even if his intentions are noble and pure.
The incidents involving the Ark testify to the fundamental connection between the Ark and the Incense. The similarity between the stories indicates that the Incense, too – like the Ark – possesses a very intensive sanctity, and therefore any inappropriate proximity to it causes death.
Incense in the Story of Korach
In Parashat Korach, as noted, the Incense features twice: first, the burning of incense is the test that determines who has been chosen by God for the role of priesthood; later, the Incense makes atonement for the people and protects them from a plague. It is surely unlikely that to identify the kohen chosen by God, a minor service would be used as a test. Conversely, if the Incense is so dangerous, if it has such great power, and if it serves as the test to identify God's chosen kohen, then it must be a service of great significance.
It is interesting to note that in the story of the plague, the role of the Incense is the opposite of what it is in the three incidents noted above. In these other stories, the Incense brings death; while in the plague, the Incense saves from death and stops the plague. The Torah explains that the Incense halts the plague by making atonement for the people. It is specifically the Incense, then, that atones for their sin and halts the plague.
D. Uniqueness of the Incense
From all of the above, we conclude that burning the Incense is not a secondary service in the Mishkan, but rather a very significant and meaningful ritual that is bound up with the revelation of the Divine Presence. It is for this reason that the Incense is referred to as "holy" and as "holy of holies;" for the same reason there is a connection between it and the Ark, and each of them brings death when approached in an inappropriate manner.
This brings us back to our original question. If the Incense is of such great importance, and it is a central part of the Mishkan service rather than an appendix to it, then why does the Torah command the building of the Incense Altar only after the end of the unit that includes all the other vessels of the Mishkan, rather than somewhere among them?
Perhaps it is specifically the separate location of this command, in relation to all the other vessels, that indicates its importance. There are two ways of emphasizing that something is important: either by mentioning it first, or by isolating it from everything else and awarding it its own special place. The Ark and the Incense Altar are the two "innermost" vessels, directly relating to the Divine Presence resting in the Mishkan. Clearly, between these two vessels, the Ark is of greater importance and it is also the innermost vessel (situated in the Holy of Holies). Therefore, it is mentioned first out of all the vessels. The importance of the Incense Altar is emphasized by means of the other option: it is removed from the other vessels and mentioned at the end of the command concerning the building of the Mishkan. Thus, God's description of the Mishkan begins with the Ark and concludes with the Incense Altar – the two most important, most internal vessels that are most closely bound up with the manifestation of God's Presence.
E. The Incense and the Soul
Let us review a few midrashim that speak about the Incense:
Incense is offered not for sin, nor for iniquity, nor for guilt, but rather out of joy. As it is written (Mishlei 27:9), "Oil and incense – the heart rejoices." The Incense is beloved to God…
When Moshe made the Mishkan and its vessels and [performed] all of the labor and the sacrifices, the Divine Presence still did not descend, until they offered incense… The Holy One, Blessed be He, said to Israel: "My children, take greater care with the Incense than with all of the sacrifices that you offer before Me, for by means of the Incense you make atonement in this world and also for the time to come." (Midrash Tanchuma, Tetzavveh 15)
There were two altars: one of gold (the Incense Altar), corresponding to a person's soul, and one of copper (the Sacrificial Altar), corresponding to a person's body. Just as gold is more precious than copper, so souls are more precious than the body. (Midrash Tadsheh 811)
These midrashim reinforce the concept of the Incense as an atonement for the soul. A person's soul is the innermost and most important part of him; likewise, offering the Incense is the innermost and most important service in the Mishkan.
The connection between the Incense and the soul is expressed on several levels: the Incense offering is a fragrance – something abstract and spiritual, something which the soul enjoys (Malbim, Shemot 30:1). The Incense, like the soul, is described as "dakka" (fine): Moshe is told, "You shall beat some of it fine" (Keli Yakar, Shemot 30:1).
Among the ingredients of the Incense we find galbanum (chelbena), which has an unpleasant smell on its own. The Sages explain that this symbolizes wicked people (Keritot 6b). The Incense, then, symbolizes the totality of all parts of the nation of Israel. Why is it specifically the Incense that symbolizes this unity? It seems that since burning the Incense is the innermost service, corresponding to the soul, the innermost part of a person, nothing else could be more appropriate as the symbol of the connection between all of Am Yisrael, the Jewish nation. At the most fundamental, spiritual source, all of Israel are holy, and God is in their midst; therefore, it is specifically the Incense that symbolizes this connection.
The claim of Korach and his company is an important one: all of Benei Yisrael "are holy, and God is in their midst." Indeed, this is true. All of Benei Yisrael are connected, at the root of their soul, to God. But what conclusion arises from this claim? In Korach's view, if everyone is connected to God at the root of his soul, then everyone is able to perform the Divine service in the Mishkan; everyone is capable of drawing close to the Divine Presence.
This is Korach's mistake. Although everyone is connected to God at the root of their soul, in reality there are differences between people, arising from either an initial appointment by God, or from a person's inner work. Proximity to the Divine Presence is dependent on the level of a person's readiness. It is not sufficient that the root of one's soul is connected to sanctity; much more than this is needed. This holy root must find expression in the reality of the person's life; only then can he approach the Sanctuary.
Why does Moshe choose the Incense as the medium for showing Korach his mistake? In light of what we have said above, we may suggest that since offering the Incense is a most significant service, related to the revelation of God's Presence, Moshe selects this as the sign. The person who is worthy of approaching the Sanctuary will succeed in his service; whoever is not worthy will die – because approaching the Sanctuary can be catastrophic if it is performed in the wrong way.
Perhaps there is another reason for Moshe's choice of the Incense. It is this mixture, representing the unification of all of the souls of Israel at their inner common point of sanctity, that could seemingly prove Korach's argument. On the surface, the Incense is indeed a sign that "the entire congregation is holy, and God is in their midst." On the other hand, as Moshe goes on to prove, it is specifically this mixture that also brings death to whoever approaches it, if he is not worthy.
Burning the Incense is the innermost and most significant service in the Mishkan, descending to the root of all Jewish souls and joining them all with their Divine source. Despite this action of connecting, the service can only be performed by a special person who is capable of reaching the innermost root of Am Yisrael and thereby making atonement for them and bringing about the revelation of God's Presence.
Our examination of the verses shows that the Incense service atones and stops the plague, but it also brings death to those who approach it. In truth, these are two sides of the same coin. The Incense penetrates to the innermost, holiest and most pure root of souls, and thereby makes atonement. But this inner connection with holiness leads to a revelation of God's Presence – and anyone who approaches His Presence in an improper manner is harmed by the intensity of His holiness.
The Incense, which connects the nation and highlights the inner spark that is common to all, may be misleading; it may convey the sense that "all are holy." It is therefore the Incense itself that proves the mistake in this way of thinking. The burning of the Incense serves to clarify that not everyone is worthy of creating that inner connection — that there are levels of holiness. The Incense must be prepared and offered in a most precise manner, by people specially chosen by God. It is therefore the Incense service that is the most appropriate test to identify who is worthy of the lofty task of joining all the souls of Israel to their source of holiness.
Translated by Kaeren Fish
 For extensive discussion see Barukh Katz, "And the Cloud of Incense Covered" (Heb.), Alon Shevut 106. This idea also appears in various VBM shiurim: Rav Yonatan Grossman, Parashat Shemini); Rav Menachem Leibtag on Parashat Tetzaveh; Rav Elchanan Samet on Parashat Tetzaveh and in his book, "Studies in the Weekly Parasha."
 See, for example, 26:35; 27:21; 40:4-5; 40:22-27. In each of these instances, the Incense Altar is described as standing "before the Veil" and in relation to the Ark, while the location of the Table and the Menora is "outside the Veil," with no relation to the Ark.
 One could still maintain that the Incense Altar serves God's revelation upon the Ark, and that its location is therefore not independent, but rather in relation to the Ark. However, we propose a more fundamental connection between God's Presence and the Incense.
 It is interesting to note that the text here mentions only that the Incense is placed before the Testimony; there is no explicit reference to the Incense Altar. The Sages teach that the Incense may be burned even in the absence of an Incense Altar (Zevachim 59a), and the Meshekh Chokhma explains that this is deduced on the basis of our verse, which makes no mention of the Incense Altar. We may therefore conclude that the Incense Altar itself is of lesser importance, and perhaps it is for this reason that it is discussed outside of the framework of all the vessels of the Mishkan, while the Incense itself is of central importance. Alternatively, we may posit that the Incense is of such great importance that it may not cease – even in the absence of the Incense Altar.
 Tzara'at is a disease that is considered like death. A person who is afflicted with it is considered like a dead person (Shemot Rabba 1:34), and as we see in the case of Uzziyyahu, his tzara'at prevents him from continuing to function as king.
 The command to build the Incense Altar is not introduced with a new Divine utterance; rather, it begins with the words, "And you shall make an altar." In other words, this is not a new beginning, but rather the continuation of a previous command – the command concerning all of the Mishkan's elements. In addition, the other vessels are all introduced with the verb "to make": "And they shall make an Ark… and you shall make a Table… and you shall make a Menora" (25:10, 23, 31). The Incense Altar follows the same formula. It is one of the vessels of the Mishkan; therefore it is included in the Divine utterance in which Benei Yisrael are commanded to make the other vessels. In contrast, the continuation of Chapter 30 features some "auxiliary" commands, and they are introduced by separate utterances: "God spoke to Moshe saying: 'When you count…' And God spoke to Moshe saying: 'You shall make a Kiyyor…' And God spoke to Moshe, saying: 'And you – take for yourself fine spices…' And God said to Moshe, 'Take for yourself sweet spices'" (vv. 11-12, 17-18, 22-23, 34). This discrepancy between these commands and the command of the Incense Altar serves to highlight the fundamental difference between the passage of the Incense Altar and the other "appendices" — and the fact that the former is an integral part of the Mishkan.
 For further discussion of the uniqueness and significance of the Incense, see the commentaries of the Ramban, Tzeror Ha-mor, Malbim, Keli Yakar, and Recanati on Shemot 30, as well as the commentary of Rabbeinu Bachya on Vayikra 10.
 See Rav Kook's Olat Ra'aya, pp. 136-138; as well as Orot, p. 32.