Exodus 28 has a fairly clear surface structure:
A.Garments of glory and beauty, 28:1-5
B. Ephod and onyx stones, 28:6-14
C. Breastpiece of judgment, 28:15-30
D. Robe of the ephod, 28:31-35
E. Golden crown, tunic, turban, 28:36-39
F. Tunics and caps for Aaron's sons, 28:40
G. Breeches to cover flesh, 28:42-43
The oddities come toward the end. Verses 2 and 40 form an inclusio with the repetition of the unique phrase "for glory and for beauty" (Heb. lekavod ultif’aret). Most of the priestly uniform is described within the frame, but the linen underclothes dangle at the end, outside the frame, perhaps an afterthought, perhaps for extra emphasis.
Another oddity arises in verses 39. Verses 36-38 describe Aaron's headgear, as does the second clause of verse 39. But a very brief reference to his "tunic of woven (shavatz) work of fine linen" and "a sash" intervenes (28:39a). Why wasn't the tunic included with the robe (28:31-35)? Apparently, because the robe is specifically the "robe of the ephod" (28:31).
Once we note that, we can see that the entire section 28:6-35 concerns the ephod - first the ephod itself, then the breastplate attached to the ephod, then the robe of the ephod. 28:36-39 includes everything else - plate, tunic, turban, sash. Of these, only the plate is described in any detail; the rest are simply listed.
The structure highlights the number seven. In the outline above, there are seven sections, some perhaps matching the creation days: garments of glory and beauty (28:2) = light (Day 1); ephod with inscribed onyx stones (28:6-14) = Aaron as firmament boundary (Day 2); Aaron's sons also wear glory and beauty (28:40) = creation of Eve (Day 6); underclothes to cover flesh and prevent guilt (28:42-43) = fall, guilt, fig leaves (Day 7).
Plus, the high priestly garments consist of seven articles. Six are listed in 28:4, but that list leaves out the golden plate (28:36-38), apparently including it with the turban. Aaron is a new man of seven, restored to Adam's glory.
What are garments for? In ancient Israel, clothing was a form of wealth, listed with silver, gold, and jewels (Genesis 24:53). As such, they formed part of the “splendor” with which a man clothed himself. In Genesis, human kavod (“glory”) is wealth (Genesis 31:1) and status (Genesis 45:13).
In the Joseph narrative, garments and robes represent office. Joseph is elevated above his brothers, and that elevation is represented in a multi-colored robe. His envious brothers strip his robe, but in Potipher’s house he receives the new garments of a steward, which are taken from him by Potipher’s wife (Genesis 39:12-18). Elevated by Pharaoh, he receives a signet ring, a golden necklace, and linen clothing (Genesis 41:42). These are the last garments mentioned in Genesis, the last garments mentioned before Exodus 28. Father Yahweh elevates His son Aaron. Aaron and his sons become stewards to a King greater than Pharaoh.
The priestly garments identify aspects of the priestly office. Aaron wears the names of the tribes of Israel twice over – on the onyx stones at his shoulders (Exodus 28:9-10), because he bears up his brothers; and on the breastplate of the ephod (Exodus 28:21), because he bears his brothers on his heart and memorializes them before Yahweh (Exodus 28:29-30). We’ll note other sartorial symbols of priesthood as we move through the chapter.
Clothing is a secondary skin and a form of housing. In Leviticus 13-14, leprosy touches the body/skin, but can also creep into clothing and stain the walls of a house. The priest’s garments are a glorious skin, partly designed to cover over shameful flesh (Exodus 28:42-43). Aaron’s uniform is made from the same blue, purple, scarlet, and gold as the tabernacle curtains (Exodus 28:5; cf. 26:1). Aaron tabernacles in glory, anticipating the One who will tabernacle in flesh.
Some clothing is used for particular occasions. The Bible speaks of festival clothing, and in Isaiah 61:10 it resembles the clothing of the high priest. Aaron is dressed for the perpetual feast of the tabernacle. With its metallic breastpiece, Aaron’s clothing is also symbolic armor, the precedent for the armor of God that both Yahweh (Isaiah 59:15-21) and we wear (Ephesians 6:10-20).
In all these respects, clothing is a human analogue to Yahweh’s glory-garments. Clothing isn’t merely functional (to protect from the elements) or moral (to cover the naked body). Clothing is symbolic theology. His cherubic attendants form a robe or a dwelling around Him. His glory flashes and shines with light, and represents His heavenly status and position. Yahweh’s glory is His armor, as He enters into battle on Israel’s behalf. Clothed in garments of glory and beauty, Aaron is the image of Yahweh’s glory.