Musannaf Ibn Abi Shayba 16:826

Abu Bakr narrated to us, he said: Al-Fadl ibn Dukayn narrated to us, he said: Abu ‘Amir Salih ibn Rustum narrated to us, he said: Humayd ibn Hilal narrated to us, he said: Al-Ahnaf ibn Qays narrated to me, he said: I arrived in Medina and entered its mosque. While I was praying, a tall, dark-skinned man entered, with a white beard and head, and he was clean-shaven, his features resembling one another. I went out and followed him, then I said: "Who is this?" They said: "Abu Dharr."