What does Genesis 19:2 mean?

He said, Please, come stay at my house tonight. Wash up, spend the night, and you can head out early in the morning. But they said, No, we'll just spend the night out here in the square. Genesis 19:2 - Modern Text Bible

(Lot offers them shelter, but the visitors initially refuse, planning to stay in the open, which was risky in Sodom.)