Musannaf Ibn Abi Shaybah 4957 — Praying in churches and synagogues

Sayyiduna Talq bin Ali (may Allah be pleased with him) said: We came as a delegation to the Prophet (peace and blessings be upon him). We said that there was a church in our land. We asked him for the leftover water of his ablution in order to purify it. He called for water and performed ablution, then rinsed his mouth, and put the remaining water in a vessel of ours and said: "Take it with you. When you reach your land, demolish your church, sprinkle this water over that place, and make that place a mosque."