Musnad Ahmad 31:172

Yazid narrated to us, Abu Mas'ud al-Jurayri informed us, from Abu Nadra, from Abu Sa'id al-Khudri, who said: We were with the Messenger of Allah, may Allah bless him and grant him peace, on a journey, and we passed by a river that had water from the water of the sky, and the people were fasting. The Messenger of Allah, may Allah bless him and grant him peace, said: "Drink." No one drank, so the Messenger of Allah, may Allah bless him and grant him peace, drank, and the people drank.