Abdullah bin Abbas and Miswar bin Makhrama had a disagreement at al-Abwa.Abdullah said, "A pilgrim in the state of ihram may wash his head."Miswar bin Makhrama said, "A pilgrim in the state of ihram may not wash his head."Abdullah bin Abbas then sent me to Abu Ayub al-Ansari. I found him bathing between two posts, screened by a cloth. I greeted him.He asked, "Who is this?"I replied, "I am Abdullah bin Hunayn. Abdullah bin Abbas has sent me to ask you how the Messenger of Allah ﷺ used to wash his head while in ihram."Abu Ayub placed his hand on the cloth and lowered it until his head became visible to me. Then he said to a person who was pouring water for him, "Pour."The man poured water over his head. Then he moved his head with his hands, bringing them forward and back, and said, "This is how I saw the Messenger of Allah ﷺ do it."
أن عبد الله بن عباس والمسور بن مخرمة اختلفا بالأبواء، فقال عبد الله: يغسل المحرم رأسه. وقال المسور بن مخرمة: لا يغسل المحرم رأسه. قال: فأرسلني عبد الله بن عباس إلى أبي أيوب الأنصاري فوجدته يغتسل بين القرنين- وهو يستر بثوب- فسلمت عليه فقال: من هذا؟ فقلت: أنا عبد الله بن حنين أرسلني إليك عبد الله بن عباس أسألك كيف كان رسول الله ﷺ يغسل رأسه وهو محرم؟ قال: فوضع أبو أبوب يده على الثوب فطأطأه حتى بدا لي رأسه ثم قال لإنسان يصب عليه: اصبب، نصب على رأسه، ثم حرك رأسه بيديه فأقبل بهما وأدبر ثم قال: هكذا رأيت رسول الله ﷺ يفعل.
Malik related it in Hajj (4) from Zayd bin Aslam, from Ibrahim bin Abdullah bin Hunain, who said, and he mentioned it. Bukhari related it in the Recompense of Game (1840), and Muslim in Hajj (1205), both of them by way of Malik, with the same chain.