Hadith 510750
Chapter 26: The 'Aqiqa - كتاب العقيقة
وَحَدَّثَنِي عَنْ مَالِكٍ، أَنَّهُ بَلَغَهُ أَنَّهُ عُقَّ عَنْ حَسَنٍ، وَحُسَيْنٍ، ابْنَىْ عَلِيِّ بْنِ أَبِي طَالِبٍ .
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.
Reference Muwatta Malik 510750
USC-MSA web (English) reference : Book 26, Hadith 64