'Unclean' in the Bible

They will not remain in the Lord's land. Ephraim will return to Egypt; they will eat ritually unclean food in Assyria.

They will not pour out drink offerings of wine to the Lord; they will not please him with their sacrifices. Their sacrifices will be like bread eaten while in mourning; all those who eat them will make themselves ritually unclean. For their bread will be only to satisfy their appetite; it will not come into the temple of the Lord.