'Pollutions' in the Bible

The Passover was eaten by the sons (descendants) of Israel (Jacob) who returned from exile and by all those who had separated themselves from the [ceremonial] uncleanness of the nations of the land to join them, in order to seek the Lord God of Israel.

which You have commanded by Your servants the prophets, saying, ‘The land which you are entering to possess is a defiled land with the uncleanness of the peoples of the lands, through their repulsive acts which have filled it from one end to the other along with their impurity.