Albert Barnes Commentary Ezekiel 42:4

"And before the chambers was a walk of ten cubits` breadth inward, a way of one cubit; and their doors were toward the north." — Ezekiel 42:4 (ASV)

Or, in the front of the chambers was a gangway of ten cubits breadth leading inward, a path of one cubit, and their doors toward the north. This gangway had stairs to the upper stories, while along the north front of the building there was a kerb of one cubit (as before the guard-chambers, Ezekiel 40:12), on which kerb the north doors (leading to the basement) opened.

Others follow the Septuagint: And opposite the chambers a walk 10 cubits in width to 100 cubits in length.