The 18th of Iyyar on which the 33rd day of the Omer coincides is a day of historical significance. On that day in the year 363, the Byzantine Roman emperor Julian in collaboration with Atiochian Jewry attempted to lay the foundations of the Third Temple in Jerusalem. For centuries afterward, the day was commemorated as a fast day. One primary source in rabbinic Judaism that references the day is Sefer Zerubavel. Given the relative obscurity of Sefer Zerubavel today, we thought that we could help remedy that on just the day it currently references in the rabbinic Jewish calendar: Lag ba-Omer — a day which otherwise lacks any liturgical reading. Below is the text of Sefer Zerubavel as found in Divrei Yeraḥmiel (according to the text transcribed and published as Sefer ha-Zikronot hu’ Divrey ha-Yamim le-Yerahme’el (ed. Eli Yassif; Tel Aviv: Tel Aviv University, 2001), pp. 427-435, set side-by-side with the English translation by the scholar John Reeves.