Musnad Abu Ya'la al-Mawsili 115:54

Hadbata narrated to us, Hammam narrated to us, Qatadah narrated to us, from Anas, that he said: I witnessed the Prophet, may Allah bless him and grant him peace, with his companions at al-Zawra’—or he said: at the houses of Medina. He wanted to perform ablution, so a bowl containing a little water was brought to him. He placed his hand upon the bowl, and the water began to spring forth from between his fingers until the entire group performed ablution. I said to Anas: "How many were you?" He said: "Approximately three hundred."