Musnad Ahmad 571:1

'Affan narrated to us, Abu 'Awanah narrated to us, Hilal ibn Abi Humayd narrated to us, from 'Abd al-Rahman ibn Abi Layla, who said: 'Umar looked at Abu 'Abd al-Hamid—or Ibn 'Abd al-Hamid, Abu 'Awanah was uncertain—and his name was Muhammad, and a man was saying to him: "O Muhammad, may Allah do to you such and such, and such and such," and he began to insult him. He said: The Commander of the Believers then said: "O son of Zayd, come near to me." He said: "Do I not see Muhammad being insulted because of you? By Allah, you shall not be called Muhammad as long as I am alive." So he named him 'Abd al-Rahman. Then he sent to the sons of Talhah so that their families would change their names, and they were seven at that time, and their master and the eldest of them was Muhammad. He said: Muhammad ibn Talhah said: "I adjure you by Allah, O Commander of the Believers, for by Allah, no one named me Muhammad except Muhammad, may Allah bless him and grant him peace." 'Umar said: "Rise, I have no way to [change] something that Muhammad, may Allah bless him and grant him peace, has named."