Ezekiel 44:22-23

Neither shall they take for their wives a widow, nor her that is put away: but they shall take maidens of the seed of the house of Israel, or a widow that had a priest before. {put...: Heb. thrust forth} {that had...: Heb. from a priest} And they shall teach my people {the difference} between the holy and profane, and cause them to discern between the unclean and the clean.