Chanuka: Shehecheyanu

Why do we say the Shehecheyanu blessing on Chanuka?

Shalom! 

Thank you for your question. 

Indeed, there is some discussion as to what role the shehecheyanu blessing actually serves, whether it is for the holiday in general (like the Shehecheyanu recited on Pesach and Sukkot, etc) or whether it is for the mitzvah of lighting the menorah in particular (like the Shehecheyanu on the shofar or the lulav). 

With minor exception, the shehecheyanu blessing that is recited on all other holidays was instituted in honor of the holiday itself, and is independent of the holiday’s accompanying mitzvot. As such, perhaps it can be suggested that Chanuka should be treated like most other holidays, and even if one is unable to light a menora, one should still recite the shehecheyanu blessing simply in honor of the holiday. 

It is also noted that the one honored to light the menora in the synagogue on the first night of Chanuka recites all three blessings when doing so. However, when this same individual returns home to light his own menora that night, he only recites the first two blessings, and omits shehecheyanu (unless he is lighting the menorah on behalf of others, as well and some say that the same halacha applies with She'osoh Nisim the rest of the days). Perhaps it can be derived from here  that even though the menora is lit in the synagogue each night of Chanuka, the one who lights it does not discharge his personal obligation to light a menora. He is still required to light a menora at home. Furthermore, since the one who lit the menora in the synagogue does not repeat the shehecheyanu blessing when lighting the menora again at home (unless he is lighting the menora on behalf of others), it implies that the shehecheyanu blessing is not necessarily exclusive to the mitzva of lighting the menora. If it were, he would be required to recite it again when lighting the menora at home, which is when he truly performs the mitzva! This suggests that the shehecheyanu blessing is related to the holiday itself rather than to the mitzva. 

Based on this unceertaintity, most authoritites rule that the shehecheyanu blessing should only be recited when lighting the menorah. Therefore, even one who, for whatever reason, will not be lighting a menora at all over the course of Chanuka should not recite the shehecheyanu blessing. Purim is identical to Chanuka for this purpose. Therefore, one who is unable to read or hear the Megilla on Purim does not recite the shehecheyanu blessing simply in honor of the holiday. 

 shehecheyanu blessing that is recited on holidays of Torah origin is in honor of the holiday itself and not necessarily related to the holiday’s accompanying mitzvot (although sometimes we do have in mind when reciting the shehechyanu to exempt the other mitzvot of the Chag). The shehecheyanu of Chanuka and Purim, however, is an inseparable component of the mitzvot of the holiday, and is not an inherent component of the holiday itself. 

OC 671, 676 and commentaries; Birkei Yosef, OC 692; Biur Halacha 692