Sahih Bukhari
Sacrifice on Occasion of Birth (Aqiqa)
Volume: 007 / Book Number: 066 / Hadith Number: 383
Narrated Abu Huraira:
The Prophet said, "Neither Fara' nor 'Atira) is permissible)." Al-Fara' was the first offspring (they got of camels or sheep) which they (pagans) used to offer (as a sacrifice) to their idols. 'Atira was (a sheep which used to be slaughtered) during the month of Rajab.