Ezra 6:20-21

20All the priests and Levites had purified themselves and were ceremonially clean.

And the Levites slaughtered the Passover lamb for all the exiles, for their priestly brothers, and for themselves. 21The Israelites who had returned from exile ate it, together with all who had separated themselves from the uncleanness of the peoples1 of the land to seek the LORD, the God of Israel.