The Mitzva of Aravos
Today, the custom to strike aravos against the ground on Hoshana Rabba is universally accepted in all Jewish communities. However, it is interesting to note that this was once not so widely practiced. Rabbeinu Mano'ach, a Rishon and one of the classic commentaries on the Rambam, notes that he remembers from his youth that only a small percentage of the elders of his town (Narvona) practiced this custom (Hilchos Lulav, 7:22). Since then, the custom has become more widely practiced. However, there are several opinions among the Poskim as to how precisely it should be performed.
Leaning the aravos against the Mizbei'ach:
The Gemara concludes that in the days of the Beis HaMikdash, the mitzva of aravos was performed by leaning aravos against the Mizbei’ach, and also by taking them in hand, as we do today with the four minim. This was a mitzva revealed to Moshe Rabbeinu on Har Sinai. According to Rashi, the Kohanim took the aravos in hand, shook them, and walked around the Mizbei'ach, before leaning them against the side of the Mizbei’ach. However, the Rambam (see Minchas Chinuch, 324:1) writes that after the aravos were leaned against the mizbei’ach, everyone, Kohanim, Yisroelim, and Leviim, took them in hand (see Ran 21b for a third opinion).
The mitzva of aravos practiced today is a custom instituted by the Prophets, in remembrance of the original mitzva practiced in the Beis HaMikdash. However, this remembrance was never meant as an absolute obligation, and therefore no beracha is recited. Rather than enacting this remembrance for all seven days of Sukkos, it was enacted on Hoshana Rabba alone, due to the great holiness of the day. In the time of the Beis HaMikdash, on Hoshana Rabba they circled the Mizbei’ach with aravos seven times (Taz, 662 s.k. 2).
Striking or shaking?
How is the custom of aravos performed today? The Gemara states in several places that the Amoraim would strike with the aravos (chavata). The Rambam rules the same. However, it is interesting to note that Rashi and Tosefos do not write that we should strike with the aravos, but rather we should shake them. Although chavata generally means to strike, we find the word used in Shas also to mean shaking. For example, the Gemara uses the word chavata to mean shaking the schach (Sukka 9b; see Korban Nesanel, 4:7). Rashi and Tosefos apparently favored that interpretation here, in regard to the custom of aravos. Rabbeinu Manoa'ch (cited above) recalled from his youth that some of the elders of his city would strike the aravos against the ground on Hoshana Rabba. He makes no mention of shaking the aravos. The Rema (662:4) writes that the custom is to fulfill both opinions cited in the Rishonim. The aravos should be both shaken and struck. The Aruch HaShulchan writes that in his days the custom was only to strike with the aravos, not to shake them. However, he concludes that it is best to abide by the Rema's ruling, by also shaking the aravos slightly. Today, many follow this conclusion.
According to the Beis Yosef, on Hoshana Rabba when we circle the bima with the four minim, we should also hold the hoshanos aravos. However, the Rema argues that it is best not to carry the hoshanos aravos around the bima. The Poskim cite the Arizal who warned very strictly against doing so (Mishna Berura ibid, s.k. 26). However, if one has no lulav with which to circle the bima, he should carry the hoshanaos aravos instead (Mishna Berura ibid, s.k. 15).
What to strike against:
The Rambam and Shulchan Aruch rule that we should strike the aravos against "the ground or any utensil.” The Meiri writes that “some pious people” would strike the aravos on the steps to the Aron Kodesh, or above its doors. The Kabbalists write that we should strike them only on the ground (Magen Avraham s.k. 6). Some hold that before striking them against the ground, we should strike them against a utensil to break off the leaves (Pri Megadim, E.A. s.k. 6). Some hold just the opposite, that we should first strike them against the ground, since this is the primary fulfillment of the mitzva. Afterwards we should strike them against a utensil to break off the leaves. Otherwise, we would render the aravos possul by breaking off their leaves, before ever a chance to fulfill the custom properly by striking the aravos against the ground (Bikurei Yaakov s.k. 16; Shaar HaTzion s.k. 12). The Mishna Berura cites this opinion as accepted halacha, and adds that one need not shake off all the leaves. However, the Kabbalists rule that one should not break off the leaves at all (Kaf HaChaim 664, s.k. 37).
