John Gill Commentary Ezekiel 42:7

"And the wall that was without by the side of the chambers, toward the outer court before the chambers, the length thereof was fifty cubits." — Ezekiel 42:7 (ASV)

And the wall that was outside over against the chambers This wall separated and distinguished the chambers from the outward court, as well as was a protection of them; and signifies the grace and power of God, which separates his true churches from the world, and is the security of them; (See Gill on Ezekiel 11:5)

this was towards the outer court, on the front part of the chambers or front of them, which seems to be to the north of them; since their doors were towards the north, (Ezekiel 42:4), though Cocceius makes it to be to the west, which better agrees with what follows:

the length thereof was fifty cubits which answers to the breadth of the chambers, (Ezekiel 42:2) and what is called length here, with respect to the wall, is called the breadth with respect to the chambers. The wall of divine protection is equal to the length and breadth, and even the whole compass, of the churches of Christ.