Ezra 6:20-21

20for every one of the kohanim and the Levites had purified themselves and all of them were ceremonially pure. They slaughtered the Passover lamb for all the exiles, and for their fellow kohanim and for themselves.

21So those of Bnei-Yisrael who had returned from the exile ate it, together with all who had separated themselves from the impurity of the nations of the land to seek Adonai the God of Israel.