Musnad Ahmad 1129:11

'Abd al-Samad narrated to us, Mulazim narrated to us, 'Abdullah ibn Badr and Siraj ibn 'Uqbah narrated to us, that their paternal uncle Qays ibn Talq narrated to him, that his father Talq ibn 'Ali narrated to him: That a delegation set out to the Messenger of Allah (peace and blessings of Allah be upon him) until they came to him. They informed him that there was a church in their land, and they asked him for the remainder of his purification water. He called for water, performed ablution, rinsed his mouth, then poured it into a leather container and said: "Go with this water, and when you arrive at your land, break down your church, sprinkle its place with this water, and take it as a mosque." We said: "O Prophet of Allah, we travel in a time of much poisonous heat and intense heat, and the water will dry up." He said: "Add water to it, for it will remain potent, abundant, and fresh." He said: So we set out until we reached our land. We broke down our church, sprinkled its place with that water, and took it as a mosque.