The Prophet ﷺ went to Zamzam, drank from it, and poured some of its water over his head.
أن النبي ﷺ ذهب إلى زمزم، فشرب منها، وصب على رأسه.
Imam Ahmad (15243) narrated it from Musa bin Dawud, who said, Sulayman bin Bilal narrated to us, from Jafar, from his father, from Jabir, and he mentioned it.Its chain is hasan because of Musa bin Dawud, who is al-Dabbi, one of the narrators of Muslim. There is disagreement about him, but his hadith is hasan. It is stated in al-Taqrib, "Truthful, a jurist, ascetic, who had some lapses."One might wonder whether his statement "and he poured it over his head" is one of his lapses, since he was alone in reporting it. This is because everyone who narrated the description of the Prophet's ﷺ Hajj from the hadith of Jabir did not mention this addition.When we looked at the other hadiths, we found that the Prophet ﷺ encouraged the use of Zamzam water to cool fever.