Hadith 906:12
'Affan narrated to us, Hammam narrated to us, from Qatadah, who said: Ibn Sirin took [the method of] his washing from Umm 'Atiyyah. She said: "We washed the daughter of the Messenger of Allah (may Allah bless him and grant him peace), and he commanded us to wash her with lotus leaves three times; if she becomes clean, [then that is sufficient], otherwise five times; if she becomes clean, [then that is sufficient], otherwise more than that." She said: "And we saw that more than that is seven."
حدثنا عفان، حدثنا همام، عن قتادة، قال: أخذ ابن سيرين غسله عن أم عطية، قالت: " غسلنا ابنة رسول الله صلى الله عليه وسلم، فأمرنا أن نغسلها بالسدر ثلاثا، فإن أنجت وإلا فخمسا، فإن أنجت وإلا فأكثر من ذلك "، قالت: " فرأينا أن أكثر من ذلك سبع "