From Sahih Bukhari (Hadith 3572):
Narrated Anas:A bowl of water was brought to the Prophet (ﷺ) while he was at Az-Zawra. He placed his hand in it and the water started flowing among his fingers. All the people performed ablution (with that water). Qatada asked Anas, "How many people were you?" Anas replied, "Three hundred or nearly three hundred
Reference: Bukhari 3572