Musannaf Ibn Abi Shayba 23:224

Affan narrated to us, he said: Sulayman narrated to us, from Humayd ibn Hilal, he said: Silah said: I saw Abu Rifa’ah after he had been afflicted, in a dream, upon a fast she-camel, while I was upon a heavy, slow-moving camel. I was following in his tracks. He said: So he would turn it [the camel] toward me, and I would say: "Now I will hear his voice." Then he would make it run, and I would follow his tracks. He said: So I interpreted my dream as taking the path of Abu Rifa’ah, and that I would exert myself in deeds after him, a great exertion.