Yahya related to me from Malik from Zayd ibn Aslam from Ibrahim ibn Abdullah ibn Hunayn from his father Abdullah ibn Hunayn that Abdullah ibn Abbas and al-Miswar ibn Makhrama once had a disagreement at 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 not wash his head.
Abdullah ibn Hunayn continued, “Abdullah ibn Abbas sent me to Abu Ayyub al-Ansari, and I found him doing ghusl between the posts of a well, screened by a garment. I greeted him and he said, ‘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 he was in ihram.'”
He continued, “Abu Ayyub put his hand on the garment and pulled it down until I could see his head. He said to the man who was pouring out the water for him, ‘Pour,’ and he poured some over his head. Then he passed his hands over his head from the front to the back and then to the front again, and then said, ‘I saw the Messenger of Allah, may Allah bless him and grant him peace, doing it like this.'”