Musnad Abu Ya'la al-Mawsili 154:55

Daud ibn ‘Amr narrated to us, [who said] Ibn Abi al-Zinad narrated to us, from his father, from ‘Urwah, from Ibn ‘Umar, who said: I said, "O Messenger of Allah, tell me a statement and make it brief, so that I may perhaps comprehend it." The Messenger of Allah, may Allah bless him and grant him peace, said, "Do not get angry." I repeated [the request] twice, and each time the Prophet, may Allah bless him and grant him peace, would return to me [saying], "Do not get angry."