Abdullah bin Ka'b narrates: After my father (Sayyiduna Ka'b bin Malik رضي الله عنه) lost his eyesight, I used to take him along with me. Whenever he heard the call to prayer for Jumu'ah, he would say, "May Allah have mercy on Sayyiduna As'ad bin Zurarah رضي الله عنه." I said, "O my father, I am amazed that whenever you hear the call to prayer for Jumu'ah, you supplicate for mercy for Abu Umamah (i.e., Sayyiduna As'ad bin Zurarah رضي الله عنه)." He replied, "O my son, he was the first person who established Jumu'ah in Madinah Munawwarah, in the stony land of Banu Bayadah, in Naqi', which was called Khazamat." I asked, "How many people were you at that time?" He replied, "We were forty people."