The Gemara (Shabbat 21b) famously establishes that although the Chanukah candles are meant to be lit outside one’s doorway, when this is not possible one may fulfill the mitzva by kindling the lights inside the home. Indeed, for many centuries it was customary to light inside the home, and many continue this practice even today, when kindling outdoors is generally considered safe.
Rav Yosef Engel, in his Gilyonei Ha-Shas (Shabbat 21b), raises the interesting question of whether one who lights the Chanukah candles indoors must extinguish them after they have burned for the minimum required duration of a half-hour. When candles are lit in the home, one benefits from the additional light, and thus the kindling of Chanukah lights inside the home would appear problematic, as Halakha forbids deriving benefit from the Chanukah candles. Of course, as Chazal themselves approved of fulfilling the mitzva by lighting inside the house, it is clear that one may do so despite the benefit that he necessarily receives from the enhanced illumination in the home. However, after the candles have burned for the minimum required duration, and one has thus fulfilled the obligation, he would perhaps be required to extinguish the candles so that he no longer derives benefit from them.
To present the counterargument to this conclusion, Rav Engel notes other instances where Halakha permits for the sake of a mitzva something which is ordinarily forbidden, even after the strict obligation has been fulfilled. One such example is berit mila, which may be performed on Shabbat (if that is the boy’s eighth day), despite the prohibition against inflicting a wound on Shabbat. Even in such a case, Halakha permits the mohel to remove not just the foreskin itself, but also the small pieces of skin that do not need to be removed for the circumcision to be valid (unless the mohel had stopped cutting before severing these pieces of skin). Since these pieces are generally removed as an enhancement of the mitzva, their removal is considered part of the mitzva such that it overrides Shabbat. Somewhat analogously, Rav Engel suggests, one may perhaps allow the Chanukah candles to continue burning and enhancing the illumination in his home beyond a half-hour, since this benefit was already permitted during the first half-hour.
Rav Engel also notes the comment of the Sefer Yerei’im (117) that one may extend the shofar sounds on Rosh Hashanah beyond the length strictly required by Halakha, despite the prohibition against producing sounds on Yom Tov. Since the mitzva of shofar requires sounding the shofar, one may elongate the sounds as part of the mitzva’s fulfillment.
Furthermore, Rav Engel notes, the Tosefta (10) discusses the case of a person who has shemen sereifa – oil of teruma which had become impure – and hosts a kohen in his home. Shemen sereifat is to be used by a kohen as fuel for fire, and nobody may benefit from this fire unless a kohen is benefitting from it at the time. Therefore, one who hosts a kohen in his home may light shemen sereifa for illumination or warmth, from which both he and the kohen benefit. The Tosefta comments that the host in this case may allow the fire to continue burning even after the kohen leaves, despite the fact that he will be benefiting from shemen sereifa alone, without sharing the benefit with a kohen. We might apply this ruling to Chanukah candles, as well, and conclude on this basis that one who lights indoors does not have to extinguish the candles after a half-hour passes, despite the benefit he will continue to receive from the candles.
Rav Asher Weiss questions Rav Engel’s entire discussion. For one thing, he writes, the Shulchan Arukh (O.C. 672:2) explicitly permits deriving benefit from the Chanukah candles after they had burned for a half-hour as Halakha requires. As we discussed yesterday, the Beit Yosef cites different views in this regard, and the Mahari Abuhav maintained that one may not derive benefit from the Chanukah candles even after they had burned for a half-hour. The Mahari Abuhav makes an exception in the case of one who had initially poured the oil with the specific intention that the candles should burn for only this minimum required duration, but generally, the light is forbidden for use even after a half-hour. Regardless, however, the Shulchan Arukh does not accept this view, and permits extinguishing and using the candles once they had burned for a half-hour. Rav Yosef Engel’s entire discussion is predicated on the assumption that the Chanukah candles remain forbidden for benefit even after they had burned for a half-hour, in contradistinction to the explicit ruling of the Shulchan Arukh.
Rav Weiss also adds another objection, which calls Rav Engel’s analysis into question even within the view of the Mahari Abuhav. Rav Engel works off the assumption that the light of Chanukah candles is forbidden for all types of benefit. The formulation of the prohibition, however, is not that the candles are forbidden for “hana’a” (“benefit” or “enjoyment”), but rather that it is forbidden “le-hishtameish” – “to use” – the light. While it might be true that the Chanukah candles (at least in ancient times, before electric lighting) enhance the illumination in the home, this enhancement does not necessarily amount to “use” of their light. Halakha forbids using the light of the Chanukah candles by doing activities such as reading and the like by the light. Simply benefitting from enhanced illumination does not constitute “use” of the Chanukah candles, and thus does not fall under this prohibition. Certainly, then, there is no question whatsoever that they candles may be allowed to remain burning in the home even after a half-hour.