The Secrets of Rebbi Shimōn ben Yoḥai is a pseudepigraphal record of the divine visions of the second-century rabbi, Shimon ben Yoḥai. Scholarly opinion about the date of its composition is divided. Adolf Jellinek thought it was likely authored during the time of the Crusades, while Heinrich Graetz thought it was likely composed in the mid-8th century. The visions described in the secrets portrays the Yishmaelites being led by a violent saviour of the Jews from the hegemony of the Byzantine Empire. It describes the events and rulers of the eighth-century Umayyad Empire, as well as eight-century battles between the Byzantines (known in the text as the Ḳenites or the Kingdom of Edōm) and the Umayyads (known in it as the Kingdom of Yishmael).

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.