Musnad Ahmad 27:2010

[Abdullah ibn Ahmad] said: I read to my father: Hammad—meaning al-Khayyat—narrated to us, Ibn Abi Dhi’b narrated to us, from al-Harith ibn Abd al-Rahman, from Hamzah ibn Abdullah ibn Umar ibn al-Khattab, from his father, who said: I had a wife under me whom Umar disliked. My father said to me: "Divorce her." I said: "No." So he went to the Messenger of Allah, peace and blessings of Allah be upon him, and informed him. He called me and said: "Abdullah, divorce your wife." He said: So I divorced her.