Musnad Ahmad 1069:2

Sufyan ibn 'Uyaynah narrated to us, Zayd ibn Aslam narrated to us, from a man, from his father or his paternal uncle, that he said: I witnessed the Prophet, peace and blessings of Allah be upon him, at Arafah, and he was asked about the *'aqiqah* (sacrifice for a newborn). He said: "I do not like disobedience (*'uquq*), but whoever has a child born to him, and he wishes to perform a sacrifice for him, then let him do so."