Musnad Ahmad 32:555

Yunus narrated to us, Hammad—meaning Ibn Zayd—narrated to us, from Thabit, from Anas: "The Prophet, may Allah bless him and grant him peace, called for water in a shallow vessel. The Messenger of Allah, may Allah bless him and grant him peace, placed his fingers into the vessel, and the water began to gush forth. The people began to perform ablution from it, and it was coming out from between his fingers." He said: "And the people were performing ablution." He said: "So I estimated the people, and they were between seventy and eighty."