It is narrated from Sayyiduna Ibn Abbas (may Allah be pleased with them both) that the Messenger of Allah (peace and blessings be upon him) came to Zamzam, and we drew a bucket for him. He drank from it, then spat (rinsed his mouth) into the bucket, then we poured it into Zamzam. Then he said: "Were it not that (people) would overcome you in this (service), I would draw (the water) with my own hand."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 11119