Ezekiel 42:13-20

13 Then he said to me, “The north and south rooms facing the temple courtyard are the priests’ rooms, where the priests who approach the LORD will eat the most holy offerings. There they will put the most holy offerings—the grain offerings, the sin offeringsa and the guilt offerings—for the place is holy.
14 Once the priests enter the holy precincts, they are not to go into the outer court until they leave behind the garments in which they minister, for these are holy. They are to put on other clothes before they go near the places that are for the people.”
15 When he had finished measuring what was inside the temple area, he led me out by the east gate and measured the area all around:
16 He measured the east side with the measuring rod; it was five hundred cubits.bc
17 He measured the north side; it was five hundred cubitsd by the measuring rod.
18 He measured the south side; it was five hundred cubits by the measuring rod.
19 Then he turned to the west side and measured; it was five hundred cubits by the measuring rod.
20 So he measured the area on all four sides. It had a wall around it, five hundred cubits long and five hundred cubits wide, to separate the holy from the common.