Musnad Abu Ya'la al-Mawsili 115:332

Abu Musa narrated to us, Muhammad bin Ja'far Ghundar narrated to us, Shu'bah narrated to us, from Qatadah, from Anas: That the Prophet (ﷺ) was at al-Zawra', and a vessel containing water was brought to him, which did not cover his fingers, or he said: which did not conceal his fingers. He commanded his companions to perform ablution, and he placed his palm into the water. We began to see the water springing forth from between his fingers until the people performed ablution. We said to Anas: "How many were you on that day?" He said: "Three hundred, or approximately three hundred."