Behind the Temple, at the extreme west of the whole area enclosed by the wall, was a large building, the purpose of which is not given it may have been used for storage. The Temple building, with the ground immediately surrounding it, was 100 cubits (about 150 feet) square.
Related Commentaries of Ezekiel 41:12
Ezekiel 41:12-14
12 Now the building that was before the separate place at the end toward the west was seventy cubits broad; and the wall of the building was five cubits thick round about, and the length thereof ninety cubits.
13 So he measured the house, an hundred cubits long; and the separate place, and the building, with the walls thereof, an hundred cubits long;
14 Also the breadth of the face of the house, and of the separate place toward the east, an hundred cubits.