The Clothing of Aaron's Sons (Exodus 28:40).
The other priests, the sons of Aaron, wore simpler clothing. They were seemingly all in white apart from their girdle which connected them with the colours of the Sanctuary. (The latter is assumed from Exodus 39:29, not stated). But these too were ‘holy' (Exodus 28:4).
“And for Aaron's sons you shall make robes, and you shall make for them girdles, and you shall make caps for them, for glory and for beauty.”
The robes of Aaron's sons were probably like Aaron's under-robe (kethoneth), from neck to toe and with sleeves. They were probably also of fine linen. The verb used may indicate that they were not patterned like Aaron's, but it may be that the patterning was assumed. They were fastened with a girdle, or belt, and they were to wear caps, probably close-fitting. Such caps were often worn in Egypt, but not by priests. The caps were to retain the hair. Man must be totally covered in the presence of God to cover his unworthiness. The letting down of the hair was also a symbol of sadness and distress (Leviticus 10:6), and this must not occur in the Sanctuary where all was joy.
The same word for robe is used of the provision of robes for Adam and Eve in the Garden (Genesis 3:21). Man in his puniness and his sinfulness must be totally covered before God. He is no longer fit to come before God as he is in himself.
We are given no information about the girdle, except that it was embroidered (Exodus 28:39), but Exodus 39:29 shows it to be of fine linen, and bluey-violet, and purpley-red, and scarlet, unless that is just describing Aaron's. The remainder of their clothes were probably white. They too were to be clothed in purity from head to foot.
Their clothes too were ‘for glory and for beauty'. As priestly garments they covered their wearers, as it were, in the glory and beauty of God, depicting their status. Indeed white robes are regularly elsewhere depicted as the mark of the heavenly and the garb of angels and of the redeemed who have died (Mark 9:3; Matthew 28:3; Mark 16:5; John 20:12; Acts 1:10; Revelation 4:4; Revelation 6:11; Revelation 7:9; Revelation 7:14; Revelation 19:14).