Musnad Ahmad 132:29

Abdullah ibn Yazid narrated to us, Sa’id narrated to us, Abu Marhum narrated to us, from Sahl ibn Mu’adh, from his father, that the Messenger of Allah (peace and blessings of Allah be upon him) said: "Whoever suppresses his rage while he is capable of executing it, Allah, Blessed and Exalted is He, will call him before the heads of all creation, until He lets him choose from whichever of the Houris he wishes."