Matthew Poole and continuators on Ezekiel 42:8

8 For the length of the chambers that were in the utter court was fifty cubits: and lo , before the temple were an hundred cubits.

See ver. 1. let. b. and ver. 7. let. z.

Some say the Angel, conducting the Prophet from these North chambers to the South, hath occasion given him to take notice of, and to measure a second time this space before the Temple; but what if the Angel, and the Prophet were now on the roof of this fifty cubits building, as they seem to be verse 5. measuring it, and thence the Angel might point to the hundred cubit space before the Temple, and bid the Prophet to mind it? The former most received suits best with the 11th. and 12th. verses.

This Verse gives us a reason, why the wall over against the chambers was but fifty cubits, it might not be more or less, because 'twas to hold exact symmetry with these buildings, which it confronted, possibly this verse may give some light to the second verse latter part.