I then enquired, “In regard to this deen, who is with you?” He replied, “A free man and a slave (referring to Hazrat Abu Bakr (radhiyallahu ‘anhu) and Hazrat Bilaal (radhiyallahu ‘anhu)).” I submitted, “I am also your follower and I wish to remain with you.” Rasulullah (sallallahu ‘alaihi wasallam) advised, “For now, return to your home. When you learn of my deen becoming dominant in the land, you may return.”

I thus embraced Islam and returned home, and continued to enquire regarding news of Rasulullah (sallallahu ‘alaihi wasallam). When Rasulullah (sallallahu ‘alaihi wasallam) migrated to Madinah Munawwarah, I presented myself before him and asked, “O Prophet of Allah (sallallahu ‘alaihi wasallam)! Do you remember me?” Rasulullah (sallallahu ‘alaihi wasallam) replied, “Yes, you are the person who approached me while I was in Makkah.” I responded, “Yes, I am the same person. O Prophet of Allah (sallallahu ‘alaihi wasallam)! Teach me something… (Rasulullah (sallallahu ‘alaihi wasallam) then taught him deen).”

(Extracted from Seeratul Mustafa 1/169-170)