Musannaf Ibn Abi Shayba 16:14

Abu Bakr narrated to us, he said: Waki’ narrated to us, from Dawud ibn Qays, from ‘Amr ibn Shu’ayb, from his father, from his grandfather, who said: The Prophet, may Allah bless him and grant him peace, was asked about the ‘Aqiqah (sacrifice for a newborn). He said: "I do not like disobedience (al-‘uquq). Whoever among you has a child born to him and wishes to perform a sacrifice for him, let him do so. For the boy, two sheep, and for the girl, one sheep."