From Sahih Muslim (Hadith 5943):
Anas b. Malik reported that Allah's Apostle (ﷺ) 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
Reference: Muslim 5943