It was narrated that Jubayr ibn Mut‘im said: The Messenger of Allah (blessings and peace of Allah be upon him) said: “As for me, I pour water over my head three times,” and he gestured with both hands..
Commentary : The Prophet (blessings and peace of Allah be upon him) explained to his ummah in both words and deeds how to purify oneself from impurity, which includes doing ghusl to cleanse oneself from janabah. In this hadith, Jubayr ibn Mut‘im narrates that the Prophet (blessings and peace of Allah be upon him) used to pour water over his head three times. Some of the Sahabah differed concerning the way in which the head is to be washed when doing ghusl to cleanse oneself from janabah, and that discussion took place in the presence of the Prophet (blessings and peace of Allah be upon him), as is mentioned in the report narrated by Muslim. Each of them demonstrated how he did it, and some of the people said: As for me, I wash my head like this, showing how much water they used and how many times they poured water over their heads, being extremely thorough in cleansing it. So the Prophet (blessings and peace of Allah be upon him) said to them: “As for me, I pour water over my head three times,” and he gestured with both hands. What that means is that he would take water in both hands, then pour it over his head, and he did that three times, to indicate the minimum amount of water that is sufficient to wash the head..