From Sahih Bukhari (Hadith 195):
Narrated Anas:It was the time for prayer, and those whose houses were near got up and went to their people (to perform ablution), and there remained some people (sitting). Then a painted stove pot (Mikhdab) containing water was brought to Allah's Messenger (ﷺ). The pot was small, not broad enough for one to spread one's hand in; yet all the people performed ablution. (The sub narrator said, "We asked Anas, 'How many persons were you?' Anas replied 'We were eighty or more"). (It was one of the miracles of Allah's Messenger (ﷺ)
Reference: Bukhari 195