Hadith 510730
Chapter 26: The 'Aqiqa - كتاب العقيقة
حَدَّثَنِي يَحْيَى، عَنْ مَالِكٍ، عَنْ نَافِعٍ، أَنَّ عَبْدَ اللَّهِ بْنَ عُمَرَ، لَمْ يَكُنْ يَسْأَلُهُ أَحَدٌ مِنْ أَهْلِهِ عَقِيقَةً إِلاَّ أَعْطَاهُ إِيَّاهَا وَكَانَ يَعُقُّ عَنْ وَلَدِهِ بِشَاةٍ شَاةٍ عَنِ الذُّكُورِ وَالإِنَاثِ .
Yahya related to me from Malik from Nafi that if any of Abdullah ibn Umar's family asked him for an aqiqa, he would give it to them. He gave a sheep as aqiqa for both his male and female children.
Reference Muwatta Malik 510730
USC-MSA web (English) reference : Book 26, Hadith 4