Musannaf Ibn Abi Shayba 24:161

Zayd ibn al-Hubab narrated to us, he said: Shu'bah ibn al-Hajjaj narrated to us, he said: 'Umarah ibn Abi Hafsah narrated to us, from Abu Mijlaz, from Qays ibn 'Abbad, who said: I went out to Medina seeking honor and knowledge. A man approached wearing a beautiful garment, and he placed his hands upon the shoulders of 'Umar. I said, "Who is this?" They said, "Ali ibn Abi Talib."