RABaD's maternal grandfather, Rabbi Yitzhak b. Yaakov Ibn Baruch of Mérida (1035–1094), who had compiled astronomical tables for the son of Shemuel ha-Nagid, was one of five rabbis in Spain renowned for their learning. Concerning the oral history of his maternal grandfather's family and how they came to Spain, the RABaD wrote: "When Titus prevailed over Jerusalem, his officer who was appointed over Hispania appeased him, requesting that he send to him captives made-up of the nobles of Jerusalem, and so he sent a few of them to him, and there were amongst them those who made curtains and who were knowledgeable in the work of silk, and whose name was Baruch, and they remained in Mérida."