Musnad Abu Ya'la al-Mawsili 129:40

Narrated to us Wahb, informed us Khalid, from Humayd, from Anas, who said: The prayer was called, so those whose houses were near the mosque stood up and performed ablution, while those who were far from the mosque remained. A vessel containing water was brought to the Messenger of Allah, may Allah bless him and grant him peace. The Prophet, may Allah bless him and grant him peace, pressed his fingers into it because of its narrowness, and the people performed ablution from it. He said: And they were approximately eighty men.