Hoshana Rabbah, the seventh and climactic day of the Hoshanot processions, preserves what the Mishnah itself already treats as an ancient practice without a stated explanation, which makes it an unusually candid case of a religious community continuing an act it inherited without a settled account of what it originally meant. The Mishnah, compiled around the turn of the third century, describes the willow-beating rite, striking bundled willow branches against the ground or a surface until the leaves fall, as a Temple-era custom, attributing it to a tradition going back to the prophets, but it offers no reason for the act itself, an admission rare in a legal literature that is otherwise diligent about grounding practices in scriptural verses or explicit reasoning.
Later commentators supplied explanations after the fact rather than recovering a lost original one: some read the falling leaves as a symbol of judgement being finalised, since Hoshana Rabbah is treated in later kabbalistic thought as the final sealing of the verdict set on Yom Kippur, extending the High Holiday judgement period by a further two weeks beyond the day itself, while others treat it simply as an act of supplication intensified to its most physical form on the festival's last and most significant day. What can be said with more confidence is the practical shape of the day: seven circuits are made instead of the single circuit of the preceding days, worshippers carry the same palm branch and citron used throughout Sukkot, and the extended prayers recited that day are considerably more elaborate than on any other day of the festival, reflecting the day's status as the close of the season even where the willow rite's own original rationale has simply not come down with it.