What does Deuteronomy 29:23 mean?

They’ll see the land burned out and wasted, nothing growing—no crops, no grass, nothing. It’ll look like Sodom, Gomorrah, Admah, and Zeboiim, which the Lord destroyed in his fierce anger. Deuteronomy 29:23 - Modern Text Bible

(He compares the devastation to the total destruction of infamous cities, showing how complete God’s judgment can be.)