Ezek 41:6

וְהַצְּלָעוֹת֩ צֵלָ֨ע אֶל־צֵלָ֜ע שָׁל֧וֹשׁ וּשְׁלֹשִׁ֣ים פְּעָמִ֗ים וּ֠בָאוֹת בַּקִּ֨יר אֲשֶׁר־לַבַּ֧יִת לַצְּלָע֛וֹת סָבִ֥יב סָבִ֖יב לִהְי֣וֹת אֲחוּזִ֑ים וְלֹֽא־יִהְי֥וּ אֲחוּזִ֖ים בְּקִ֥יר הַבָּֽיִת׃

The side rooms were arranged one above another in three levels of thirty rooms each. There were ledges all around the wall of the temple to serve as supports for the side rooms, so that the supports would not be fastened into the wall of the temple itself.