Yahya related to me from Malik that he heard that there had been an aqiqa for Hasan and Husayn, the sons of Ali ibn Abi Talib.

وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّهُ عُقَّ عَنْ حَسَنٍ، وَحُسَيْنٍ، ابْنَىْ عَلِيِّ بْنِ أَبِي طَالِبٍ ‏.‏
USC-MSA web (English) reference : Book 26, Hadith 64
Arabic reference : Book 26, Hadith 1075