וַיִּתֵּ֨ן עָלָ֜יו אֶת־הַכֻּתֹּ֗נֶת וַיַּחְגֹּ֤ר אֹתוֹ֙ בָּֽאַבְנֵ֔ט וַיַּלְבֵּ֤שׁ אֹתוֹ֙ אֶֽת־הַמְּעִ֔יל וַיִּתֵּ֥ן עָלָ֖יו אֶת־הָאֵפֹ֑ד וַיַּחְגֹּ֣ר אֹת֗וֹ בְּחֵ֙שֶׁב֙ הָֽאֵפֹ֔ד וַיֶּאְפֹּ֥ד ל֖וֹ בּֽוֹ׃
他給亞倫穿上內袍，束上腰帶，又給他穿上外袍，再給他穿上以弗得，用以弗得上巧工織成的帶子束住他，把以弗得繫緊在他身上。
Meshekh Chokhmah
Girded him with the sash. The garments of the kohanim atone for sin. For example, the ephod atones for idolatry, the pants atone for illicit relations, and the tunic for bloodshed (Zevachim 88). Chazal said that one punished even for his thoughts about transgressing only by idolatry. Therefore, the Kohein Godol’s sash, which atones for idolatry, must atone for thoughts as well, and thus it is a mixture of wool and linen like the ephod. However, an ordinary kohein’s garments atone for illicit relations and bloodshed, in which thoughts are not considered like deeds, and therefore their sashes are not a mixture of wool and linen.