Yehezkiel 41:6

41:6 The side chambers were in three stories, one above the other, thirty in each story. There were offsets in the wall all around to serve as supports for the side chambers, so that the supports were not in the wall of the temple.

Yehezkiel 44:11

44:11 Yet they will be ministers in my sanctuary, having oversight at the gates of the temple, and serving the temple. They will slaughter the burnt offerings and the sacrifices for the people, and they will stand before them to minister to them.