Sifra / Torath Kohanim (miluim section); parallel to the detailed clothing of Aaron.
Translation: He clothed them with tunics, girded them with sashes, and bound turbans on them — as Hashem commanded Moshe. The dressing, girding, and binding were performed in the order of the command, teaching that every detail of the miluim is indispensable.
Middah: Custom.