The Nature of the Blessing of "She-assa Nissim"
The mitzva of lighting Chanuka candles is unique in possessing two layers of performance. Generally, a mitzva is simply an obligation to fulfill a specific action commanded in the Torah. Obviously, each mitzva possesses symbolism and accentuates specific components of the religious experience. However, these characteristics are not halakhically incorporated as part of the mitzva proper. For example, the symbolism latent within the mitzva of shilua'ch ha-ken (sending away a mother bird before recovering her eggs), as profound as it seems, in no way affects the actual execution of the mitzva. Surely, awareness of this symbolism enhances performance of the mitzva on a personal level. But even devoid of these symbols, the mitzva can be performed.
By contrast, lighting candles on Chanuka incorporates a second dimension as part of the fulfillment of the mitzva itself. That second dimension, pirsumei nissa (publicizing the terms of the miracle), directly affects the manner and style in which the mitzva is performed. Essentially, by lighting candles an individual fulfills both a mechanical mitzva as well as a second facet of publicizing the miracle of Chanuka.
Assuredly, the two most conspicuous reflections of this duality are the timing and location of the mitzva. As the gemara in Shabbat (21b) asserts, the candles should be lit while people are returning from work, in order to ensure maximum publicity. In addition, the menora should be lit at the entrance of one's residence to guarantee maximal visibility. These two familiar halakhot reaffirm the presence of pirsumei nissa as an additional halakhic component of the mitzva.
There are, however, several additional manifestations of the pirsumei nissa element of hadlakat neirot. Generally, a mitzva which contains an additional halakhic feature warrants an additional blessing. Tefillin and berit mila are two examples of mitzvot which are multi-layered and accompanied by two blessings. The presence of an additional blessing when lighting candles – the blessing of she-assa nissim - might confirm the existence of an additional layer to this mitzva, depending on how we understand this additional blessing.
Perhaps the blessing should be classified as a birkat ha-shevach – a blessing recited in praise of extraordinary natural or historical events. A classic example of a birkat ha-shevach is the blessing recited when hearing thunder or witnessing lightning. As no mitzva is being performed, the blessing cannot be defined as a birkat ha-mitzva. Might the blessing of she-assa nissim – recited when lighting candles - be similarly defined as a birkat ha-shevach - a blessing recited in PRAISE of the miracle, praise which is elicited by seeing the candle? As such, she-assa nissim would not be classified as a birkat ha-mitzva and would not be indicative of a second level to the halakhic execution of the mitzva.
The question of how to define she-assa nissim – and, by extension, whether its recitation confirms a second tier to the performance of the mitvza - could potentially yield an important practical difference: when should the blessing of she-assa nissim be recited? Classically, a blessing on a mitzva is recited prior to the performance of the mitzva, while a birkat ha-shevach – which responds to a phenomenon - is recited after witnessing the given phenomenon. Should she-assa nissim be recited prior or subsequent to the actual lighting of the candles?
The Ritva in Masekhet Shabbat claims that the blessing of le-hadlik ALONG WITH she-assa nissim should precede the actual lighting, and the Rema in Orach Chayim 670:2 adopts this position. This ruling would imply that we view she-assa nissim as a birkat ha-mitvza recited upon the pirsumei nissa component of the mitvza. By contrast, Masekhet Sofrim (20:6) asserts that the blessing should be recited AFTER lighting the candles. Rav Chayim Brisker asserted the following compromise position: On each evening he would recite the blessing of le-hadlik, light one candle and then recite she-assa nissim prior to lighting the additional candles. In this manner, he was able to fulfill the Rema's position of reciting she-assa nissim prior to lighting the full quota of that night's candles, while also allowing she-assa nissim to function as a birkat ha-shevach recited after an event and in response to an event – thereby satisfying Masekhet Sofrim's position as well. Of course, the first night of Chanuka does not accommodate this compromise, and on that night Rav Chayim would adhere to the ruling of the Rema and recite both berakhot prior to lighting the first candle.
Logically, the very same question of how to understand the blessing of she-assa nissim would apply to this blessing's recitation before reading the Megilla. Should this blessing be viewed as a birkat ha-shevach recited in gratitude for the miracle of Purim, or as a birkat ha-mitzva recited on the added component of pirsumei nissa? Interestingly, no opinion claims that we should recite this blessing after reading the Megilla – in part because a post-reading blessing is already recited – "ha-rav et riveinu."
Understanding the nature of she-assa nissim might impact upon an interesting debate regarding the conditions under which this blessing is recited. The gemara in Shabbat (25a) claims that she-assa nissim is recited even upon witnessing someone else's candles. After all, praising the event of a miracle or experiencing the publicity of a miracle does not demand personal lighting - these experiences may be achieved even second-hand by witnessing the candles of others. There is, however, a dispute between several Rishonim concerning whether reciting she-assa nissim upon personal lighting is preferable to reciting it upon witnessing the candles of others. The Rashba, for example, in his comments to that gemara, claims that only someone who will not subsequently light his own candles should recite the blessing of she-assa nissim upon witnessing other people's candles. In essence, it is preferable to recite she-assa nissim upon candles a person himself lights. Rashi's comments to that same gemara, as well as those of the Ritva, suggest a parity between she-assa nissim on personal candles and she-assa nissim upon witnessing the candles of others. For example, Rashi claims that even someone who intends to ultimately light his own candles should, upon first witnessing someone else's candles, recite a blessing of she-assa nissim.
This debate as to whether she-assa nissim is superior when recited upon personal lighting would clearly stem from our understanding of the blessing. If it were purely a responsive birkat ha-shevach, praising the event of the miracle of Chanuka, it would be difficult (but not impossible) to differentiate between personal performance and second-hand experience; either situation facilitates offering praise in response to the memory of the event which is elicited through candles. However, if she-assa nissim constitutes a blessing recited upon performing the act of publicizing, one can easily envision a fundamental difference between passively noticing another's publicizing and actively contributing a personal message. Viewing she-assa nissim as a birkat ha-mitvza might account for the Rashba's prioritizing recitation upon personal performance over second-hand recitation.