Middos4: 4
הַתַּחְתּוֹנָה חֲמִשָּׁה, וְרֹבֵד שִׁשָּׁה. וְהָאֶמְצָעִית שִׁשָּׁה, וְרֹבֵד שֶׁבַע. וְהָעֶלְיוֹנָה שֶׁבַע, שֶׁנֶּאֱמַר: ”הַיָּצִיעַ הַתַּחְתּוֹנָה חָמֵשׁ בָּאַמָּה רָחְבָּהּ וְהַתִּיכֹנָה שֵׁשׁ בָּאַמָּה רָחְבָּהּ וְהַשְּׁלִישִׁית שֶׁבַע בָּאַמָּה רָחְבָּהּ”.
The [cells of the] bottom [level were] five [amos wide], and [with] the ledge [were] six [amos]. The [cells of the] middle [level were] six [amos wide], and [with] the ledge [were] seven [amos]. The [cells of the] top [level were] seven [amos wide]. As it is stated (I Kings 6:6): The lowest cell, five amos was its width; the middle one, six amos was its width; and the third one, seven amos was its width.