Musnad Abu Ya'la al-Mawsili 209:79

Zuhayr narrated to us, Ibn 'Uyaynah narrated to us, from Ayyub ibn Musa, from Sa'id ibn Abi Sa'id, from 'Abdullah ibn Rafi', from Umm Salamah, that she said to the Prophet (peace be upon him): "I am a woman who braids her hair tightly; should I undo it for the bath of major ritual impurity (janabah)?" He said: "It is sufficient for you to pour three handfuls of water over it, then pour water over yourself, and then you will have become purified."