Musnad Ahmad 32:408

I read to Abd al-Rahman, [from] Malik: from Ishaq ibn Abdullah ibn Abi Talha, from Anas ibn Malik, who said: I saw the Messenger of Allah, may Allah bless him and grant him peace, when the time for the afternoon prayer (Asr) arrived. The people sought water for ablution but did not find any. Then, the Messenger of Allah, may Allah bless him and grant him peace, was brought his ablution water. The Messenger of Allah, may Allah bless him and grant him peace, placed his hand in that vessel and commanded the people to perform ablution from it. I saw the water springing forth from beneath his fingers. The people performed ablution until they had all performed ablution, down to the very last of them.