مُوَطَّأُ مَالِكٍ
Muwatta Malik 1072
The 'Aqiqa
وَحَدَّثَنِي عَنْ مَالِكٍ، عَنْ رَبِيعَةَ بْنِ أَبِي عَبْدِ الرَّحْمَنِ، عَنْ مُحَمَّدِ بْنِ عَلِيِّ بْنِ الْحُسَيْنِ، أَنَّهُ قَالَ وَزَنَتْ فَاطِمَةُ بِنْتُ رَسُولِ اللَّهِ صلى الله عليه وسلم شَعَرَ حَسَنٍ وَحُسَيْنٍ فَتَصَدَّقَتْ بِزِنَتِهِ فِضَّةً .
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, (ﷺ), weighed the hair of Hasan and Husayn, and gave away in sadaqa the equivalent weight in silver."
Arabic/English book reference: Book 26, Hadith 3