Al-Ahnaf bin Qays narrates from a cousin of his, who said: I said: O Messenger of Allah, tell me something, and keep it brief so that I can understand it. He (peace and blessings be upon him) said: "Do not become angry." I repeated my request several times, and each time the Messenger of Allah (peace and blessings be upon him) said the same: "Do not become angry."
Hadith Referenceالمعجم الكبير للطبراني / باب الجيم / 2087