וְגָדֵ֤ר אֲשֶׁר־לַחוּץ֙ לְעֻמַּ֣ת הַלְּשָׁכ֔וֹת דֶּ֛רֶךְ הֶחָצֵ֥ר הַחִֽצוֹנָ֖ה אֶל־פְּנֵ֣י הַלְּשָׁכ֑וֹת אָרְכּ֖וֹ חֲמִשִּׁ֥ים אַמָּֽה׃
And the wall that was without by the side of the chambers, toward the outer court in front of the chambers, the length thereof was fifty cubits.
Rashi on Ezekiel
And the outer wall, etc. that intervenes between the chambers and the Outer Court of the eastern side.