The 'Aqiqa
Malik :: Book 26 : Hadith 26.1.3
Yahya related to me from Malik from Rabia ibn Abi Abd ar-Rahman that Muhammad ibn Ali ibn al-Husayn said, "Fatima, the daughter of the Messenger of Allah, may Allah bless him and grant him peace, weighed the hair of Hasan and Husayn, and gave away in sadaqa the equivalent weight in silver."