Musnad Ahmad 26:653

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Sulayman, who said: I heard Abu Wa’il narrating from ‘Abdullah, who said: It is as if I am looking at the Prophet, may Allah bless him and grant him peace, while he was telling the story of a prophet who said: "His people used to beat him until he fell unconscious." He said: Then he would wipe his forehead and say: "O Allah, forgive my people, for they do not know."