'Uncleanness' in the Bible

The Israelites who had returned from exile ate it, together with all who had separated themselves from the uncleanness of the Gentiles of the land in order to worship Yahweh, the God of Israel.

You gave through Your servants the prophets, saying: “The land you are entering to possess is an impure land. The surrounding peoples have filled it from end to end with their uncleanness by their impurity and detestable practices.