20For the priests and the Levites had purified themselves together; all of them were clean. So they slaughtered the Passover lamb for all the returned exiles, for their fellow priests, and for themselves.
In Exodus 12:6 it was the members of the community of Israel that slaughtered the Passover lamb. In Ezra 6:20 it is the Levites. During the course of the Old Testament, it seems as if this task was also done by the Levites to help the people.
20 For the priests and the Levites had purified themselves together; all of them were clean. So they slaughtered the Passover lamb for all the returned exiles, for their fellow priests, and for themselves.