Rabbi David ben Yehuda HeChassid was an important connection between the Rishonim and the Acharonim and between Sefardim and Ashkenazim in the Middle Ages. Scholars today believe he was the grandson of Ramban, and although he was not related to Yehuda HeChassid (in spite of his name), he was known to be a student of the latter’s disciple, Rabbi Eleazar of Worms. Although he was of Spanish extraction (and probably Sefardi in custom), he was fascinated by the emerging traditions that would shape Ashkenazi Judaism, and though he was directly associated with his grandfather’s school of mysticism, he is known to have been intimate with the earliest disseminators of the Zohar and was probably one himself.
His intellect encompassed many topics and he integrated a great variety of different approaches to Torah knowledge in his writings. However, these writings fell into unjustified obscurity for many hundreds of years. There are probably a number of reasons for this, including the simple fact that between the emergence of the Zohar on the one hand, and the prominence of the Tosafot and the Chassidei Ashkenaz on the other, he wasn’t readily associated with any recognized mainstream school, while the reproduction of books was a significant investment before the invention of the printing press.
Some of his most important contributions to Jewish mysticism are in the form of diagrams that were particularly unsuited to widespread transmission by the technology of his era. However, of the earliest examples of these to be reproduced by means of special printing dies, many scholars believe they were closely derivative or even exact reproductions of Rabbi David’s original work. These include the diagrams that accompany the commentary of the Ra’avad to the Sefer Yetzira (probably misattributed, as several of Rabbi David’s books would later be) and those that were included in the first editions of Pardes Rimonim of the Ramak.
Rabbi David ben Yehuda HeChassid wrote a commentary on the siddur, including the customs of prayers of holidays, called Or Zarua. This was written approximately a hundred years after the book of the same name by R’ Yitzchak of Vienna (better known as the Or Zarua). The title of Rabbi David’s book was probably a deliberate homage to this earlier text because they both deal with the nuances of prayer and, as noted, Rabbi David was a known admirer of the Chassidei Ashkenaz. On Sukkot specifically, Rabbi David is one of the earliest to document the custom of Ushpizin, although his description bears little resemblance to the practice we are familiar with. These Zoharic themes appear prominently in his commentary, and are particularly worthy of note in connection with the final days of the holiday – Hoshana Raba and Shemini Atzeret.
In his commentary, Rabbi David refers to Hoshana Raba at one point as “Arava Day,” an interesting inversion because of course aravot are conspicuous in our observance of the day and we refer to the bundle we beat at the conclusion of our prayer as hoshanot. He explains that according to the Gemara (Rosh Hashana 16b), the judgment of the “intermediate” souls is concluded on Hoshana Raba, and the Heavenly Court sitting in judgment spans Yachin and Boaz (the two columns flanking the entrance to the heichal in the Beit HaMikdash), signifying mercy and judgment, respectively. On Hoshana Raba, aravot were brought from beside a river outside of Yerushalayim to adorn the sides of the mizbe’ach. The aravot are literally arvei nachal, willow branches from beside a stream, and streams in Jewish mysticism invariably flow back to the original rivers that flowed from the Garden of Eden. The willows are a special conduit that draws the blessings and bounty out of this water and it is transplanted to the Temple Mount where many of the people of Israel face their final judgment.
During Sukkot, the mizbe’ach was circled seven times with these aravot at the same time that it was itself surrounded by them. We have retained the custom of circling the synagogue on Sukkot but the specific reference to seven circuits in our practice has been reserved for Simchat Torah. Many people have the custom of connecting these circuits to the seven “guests” from our sukkah, and Rabbi David in Or Zarua was one of the first – if not the first – to make this explicit. He explains further that the three pilgrimage festivals, Shalosh Regalim, are each “legs” (literally: regel), and Shemini Atzeret (and outside of Israel, Simchat Torah) is a Regel unto itself (Rosh Hashana 4b). Similarly, the Divine Chariot, representing Hashem’s mercy, has three wheels (or legs) corresponding to the three patriarchs, but the fourth leg is David HaMelech, completing the set.
In this way he connects the seventh day of Sukkot (or Hoshana Raba), that is the day of David with the holiday of Shemini Atzeret that follows. Just as David receives and concentrates all of the wisdom of his (and our) ancestors, in anticipation of his role as our king and redeemer, so Shmini Atzeret receives and concentrates all of the happiness and holiness of the preceding three holidays, including the seven days of Sukkot.