When the Prophet ﷺ performed the ritual bath from major impurity, he would call for a vessel about the size of a milking pail, take some water in his palm, and begin with the right side of his head, then the left, pouring it over his head with both hands.
كان النبي ﷺ إذا اغتسل من الجنابة دعا بشيء نحو الحلاب، فأخذ بكفه فبدأ بشق رأسه الأيمن، ثم الأيسر، فقال بهما على رأسه.
Bukhari related it in the chapter on ghusl (258) and Muslim in the chapter on menstruation (318), both of them from Muhammad bin Muthanna, who said, Abu Asim narrated to us from Hanzala bin Abu Sufyan, from Qasim, from Ayesha, and she then narrated the hadith. The wording given is Bukhari's, and Muslim's wording is similar, except that after the words "then the left," he said, "then he took his palms and passed them over his head."As for the word hilab, with a kasra on the unpointed ha, Khattabi said it is a vessel that holds about the amount milked from a she-camel. He said, Muhammad bin Ismail mentioned it in his book Jami Sahih and interpreted it as referring to the use of purifying perfume. I think he mistakenly supposed that what was meant by it was the mihlab used for washing the hands, but this has nothing whatsoever to do with perfume. End of his statement.Ismaili also said in his Mustakhraj, "May Allah have mercy on Abu Abdullah," meaning Bukhari, "for who is ever safe from error? It occurred to him that hilab meant perfume, but what sense would perfume make during the washing before the actual ghusl? Rather, hilab is simply a vessel, the thing one milks into, also called jilab and mihliya." Fath al-Bari (1/369).I say, this is because Bukhari, may Allah Almighty have mercy on him, entitled a chapter in his Sahih, "Chapter on one who begins with hilab or perfume during ghusl," under the impression that hilab was a type of perfume.