Musnad Ahmad 32:1018

Muhammad ibn Abdullah narrated to us, Humayd narrated to us, from Anas, who said: A man called out, "O Abu al-Qasim!" The Prophet, peace and blessings of Allah be upon him, turned toward him. The man said, "O Messenger of Allah, I did not mean you; I only called for so-and-so." He said, "Name yourselves with my name, but do not use my kunya (patronymic)."