Musnad Ahmad 33:184

Sufyan narrated to us, from Ibn al-Munkadir, who heard Jabir ibn Abdullah saying: A boy was born to a man among us, and he named him al-Qasim. We said: "We will not give you the kunya (patronymic) Abu al-Qasim, nor will we gladden your eye." So he came to the Prophet, peace and blessings of Allah be upon him, and mentioned that to him. He said: "Name your son Abd al-Rahman."