PlutarchQuaestiones Convivales, IV, 4:4 – 6:2, pp. 669 C – 672 B

(6:2) At this, all did urge him (i.e. Moeragenes) and beg him to go on. “First”, he said, “the time and character of the greatest, most sacred holiday of the Jews clearly befit Dionysus. When they celebrate their so-called Fast (i.e. Yom Kippur), at the height of the vintage, they set out tables of all sorts of fruit under tents and huts plaited for the most part of vines and ivy. They call the first of the days of the Feast Tabernacles (i.e. Sukkot).  A few days later they celebrate another festival, this time identified with Bacchus not through obscure hints but plainly called by his name, a festival that is a sort of ‘Procession of Branches’ or ‘Thyrsus Procession,’ (i.e. Shemini Atzeret) in which they enter the temple each carrying a thyrsus.

Source: Menahem, Stern.  Greek and Latin Authors on Jews and Judaism. Volume 1 (p. 557)