"A group from the people of "Iraq came to "Umar and when they came to him, he said to them: "Where are you from?' They said: "From the inhabitants of "Iraq.' He said: "Have you come with permission?' They said: "Yes.' Then they asked him about a man's prayer in his house. "Umar said: "I asked the Messenger of Allah (ﷺ) and he said: "As for a man's prayer in his house, it is light, so illuminate your houses.'" " Another chain with similar wording.