Ibn Abbas

Abd-Allah ibn Abbas (Arabic: عبد الله ابن عباس ) was a cousin of Muhammad. He is revered by Shi'a and Sunnis alike for his knowledge. He had memorized the Qur'an  and was an expert in its exegesis, as well as an authority on the Sunnah of Muhammad due to his zeal in acquiring new knowledge.
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[Islamic] Abdullah, son of Abbas, and so a cousin of Muhammad, to whom Jibril explained the Qur'an. He became the ancestor of the Abbasids.