Sahih al-Bukhari 5474Book 71, Hadith 9
حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، حَدَّثَنَا سُفْيَانُ، قَالَ الزُّهْرِيُّ حَدَّثَنَا عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ " لاَ فَرَعَ وَلاَ عَتِيرَةَ ". قَالَ وَالْفَرَعَ أَوَّلُ نِتَاجٍ كَانَ يُنْتَجُ لَهُمْ، كَانُوا يَذْبَحُونَهُ لِطَوَاغِيتِهِمْ، وَالْعَتِيرَةُ فِي رَجَبٍ.
The Prophet (ﷺ) 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.