The Book Pertaining to the Excellent Qualities of the Holy Prophet (may Peace be upon them) and His Companions (Kitab Al-Fada'il)
Muslim :: Book 30 : Hadith 5658
Anas b. Malik reported that Allah's Apostle (may peace be upon him) and his Companions were at a place known as az-Zaura' (az-Zaurd' is a place in the bazar of Medina near the mosque) that he called for a vessel containing water. He put his hand in that. And there began to spout (water) between his fingers and all the Companions performed ablution. Qatada, one of the narrators in the chain of narrators, said: Abu Hamza (the kunya of Hadrat Anas b. Malik), how many people were they? He said: They were about three hundred.