'Impurity' in the Bible

the family of the house of Levi by itself with their wives by themselves, the family of Shimei by itself with their wives by themselves

“On that day a fountain will be opened for the house of David and for the residents of Jerusalem, to wash away sin and impurity.

It will come to pass in that day, says Yahweh of Armies, that I will cut off the names of the idols out of the land, and they will be remembered no more. I will also cause the prophets and the spirit of impurity to pass out of the land.