Musnad Ahmad 32:888

Sahl narrated to us, from Humayd, from Anas, that the Prophet, peace and blessings of Allah be upon him, was wounded on the day of Uhud, and they broke his incisor tooth. He began wiping the blood from his face while saying: "How can a people prosper who have stained the face of their Prophet with blood, while he calls them to their Lord?" Then it was revealed: "Not for you is the decision whether He turns in mercy to them or punishes them, for they are indeed wrongdoers." [Al-Imran: 128]