Imaam Muzani (rahimahullah) reports:

On one occasion, we were present by Imaam Shaafi‘ee (rahimahullah) when an old man wearing woolen clothing appeared. The old man then asked Imaam Shaafi‘ee, “May I ask a question?” Imaam Shaafi‘ee (rahimahullah) gave him permission. He then asked, “What are the Shar’ee proofs in the Deen of Allah Ta‘ala?” Imaam Shaafi’ee (rahimahullah) replied, “The Kitaab of Allah Ta‘ala.” He then asked, “And what else?” Imaam Shaafi’ee (rahimahullah) replied, “The Sunnah of Rasulullah (sallallahu ‘alaihi wasallam). He then asked, “And what else?” Imaam Shaafi‘ee (rahimahullah) replied, “The consensus of the Ummah.” He then asked, “What is your proof for this?” Imaam Shaafi‘ee (rahimahullah) thought for a while. The old man then said, “I give you respite for three days, either you bring me proof from the Qur’aan, or seek forgiveness and repent to Allah Ta‘ala.”