ELI5: Explain Like I'm 5

Impurity of the land of the nations

Impurity of the land of the nations means that people have been using the land in ways that can harm it. This could be things like cutting down too many trees, building factories that release pollution, or leaving too much waste on the land. All of these things can make the land less healthy and less able to provide the things that people need from it, such as food and clean air.