וַיִּבֶן֩ אֶת־עֶשְׂרִ֨ים אַמָּ֜ה מירכותי [מִֽיַּרְכְּתֵ֤י] הַבַּ֙יִת֙ בְּצַלְע֣וֹת אֲרָזִ֔ים מִן־הַקַּרְקַ֖ע עַד־הַקִּיר֑וֹת וַיִּ֤בֶן לוֹ֙ מִבַּ֣יִת לִדְבִ֔יר לְקֹ֖דֶשׁ הַקֳּדָשִֽׁים׃
他又在殿的後部用香柏木板建造那二十肘，從地面一直到天花板；他在殿內把這部分建為內殿，作為至聖所。
Rashi
The twenty amohs at the end of the Beis Hamikdosh. The twenty [amohs] which were at the end of the Sanctuary and beyond, and the twenty [amohs] which were at the end of the building, they are the house containing the Ark cover (i.e., the Holy of Holies).
Rashi
To the ceiling. He made the walls of cedar until the ceiling to cover the walls of stone in order to coat it with gold.
Rashi
On the inner side of the partition. Inward of the “Amma Traksin” [partition], which separated between the forty [amohs] and the twenty [amohs], and that partition is called “Dvir.”25Also, “Dvir” sometimes means the Holy of Holies. See Rashi in v. 5 above and also the Metzudas Tzion there.