Musnad Abu Ya'la al-Mawsili 3:35

Muhammad ibn Abdullah ibn Ammar narrated to us, Mu'afa ibn Imran narrated to us, from Mukhtar al-Tammar, from Abu Matar al-Basri, who said: I was with Ali, and we reached the Great Market. He looked at an old man among them and said, "O old man, treat me well in the sale of a shirt for three dirhams." He said, "Yes, O Commander of the Faithful." But when he recognized him, he did not buy anything from him. He came to a young boy and bought a shirt from him for three dirhams. He wore it, and it reached from his wrists to his ankles. He said while putting on his garment, "Praise be to Allah who has provided me with clothing with which I may beautify myself among the people and cover my nakedness." The Muslims said, "Is this something you are saying about yourself, or is it from the Prophet, may Allah bless him and grant him peace?" He said, "I heard the Prophet, may Allah bless him and grant him peace, say that when he put on a garment."