Musnad Ahmad Hadith 12412

Thabit (may Allah have mercy on him) says that once I asked Anas (may Allah be pleased with him), "O Abu Hamzah! Tell us about some strange incident in which you yourself were present and you are not narrating it from anyone else?" He replied, "Once the Prophet (peace and blessings of Allah be upon him) led the Zuhr prayer and then went and sat at the place where Jibreel (peace be upon him) used to come to him. Then Bilal (may Allah be pleased with him) came and gave the adhan for Asr. Every person who had a house in Madinah Munawwarah got up and went for relieving himself and for ablution. Some Muhajireen remained who had no house in Madinah. A large vessel of water was brought to the Prophet (peace and blessings of Allah be upon him). The Prophet (peace and blessings of Allah be upon him) placed his palms in it, but the vessel was not spacious enough, so the Prophet (peace and blessings of Allah be upon him) placed only four fingers in it and said, 'Come close and perform ablution from it.' At that time, the blessed hand of the Prophet (peace and blessings of Allah be upon him) was in the vessel. So all of them performed ablution from it, and there was not a single person left who did not perform ablution." I asked, "O Abu Hamzah! In your opinion, how many people were there?" He replied, "Between seventy and eighty."