Ezekiel 44:23

to separate between the unclean and the clean, and between the edible creature and the creature which is not to be eaten.

“Then the priest shall look at the mark and shall isolate the article with the mark for seven days.

Therefore thus says Yahweh, “If you return, then I will cause you to return— Before Me you will stand; And if you extract the precious from the worthless, You will become My mouthpiece. They for their part may turn to you, But as for you, you must not turn to them.

“Her priests have done violence to My law and have profaned My holy things; they have made no separation between the holy and the profane, and they have not made known the difference between the unclean and the clean; and they hide their eyes from My sabbaths, and I am profaned among them.

He measured it on the four sides; it had a wall all around, the length 500 and the width 500, to divide between the holy and the profane.