Yahya related to me from Malik from Zayd ibn Aslam from Ibrahimibn Abdullah ibn Hunayn from his father Abdullah ibn Hunayn thatAbdullah ibn Abbas and al-Miswar ibn Makhrama once had a disagreementat al-Abwa. Abdullah said that some one in ihram could wash his head,and al Miswar ibn Makhrama maintained that some one in ihram could notwash his head.Abdullah ibn Hunayn continued, "Abdullah ibnAbbas sent me to Abu Ayyub al-Ansari, and I found him doing ghuslbetween the posts of a well, screened by a garment. I greeted him andhesaid, 'Who is that?' I replied, 'I am 'Abdullah ibn Hunayn.'Abdullah ibn Abbas sent me to you to ask how the Messenger of Allah,may Allah bless him and grant him peace, used to wash his head when hewas in ihram.' "He continued, "Abu Ayyub put his hand on thegarment and pulled it down until I could see his head. He said to theman who was pouring out the water for him, 'Pour,' and he poured someover his head. Then he passed his hands over his head from the frontto the back and then to the front again, and then said, 'I saw theMessenger of Allah, may Allah bless him and grant him peace, doing itlike this.' "
USC-MSA web (English) reference: Book 20, Hadith 4
Arabic reference: Book 20, Hadith 711