Musannaf Ibn Abi Shayba 23:182

Affan narrated to us, he said: Hammad bin Salamah narrated to us, from Ali bin Zaid, from Anas, that the Messenger of Allah (ﷺ) said: "I saw in what the sleeper sees, as if I were riding behind a ram, and as if the pommel of my sword had broken. So I interpreted it that I would kill the commander of the battalion." Affan said: "There was something after this, but I do not know what it was."