Ezra 6:20-21

20For the priests and the Levites had purified themselves; all of them were ritually clean. And they slaughtered the Passover lambs for all the descendants of the captivity, for their brethren the priests, and for themselves.

21Then the children of Israel who had returned from the captivity ate together with all who had separated themselves from the filth of the nations of the land in order to seek the Lord God of Israel.