Exodus 25:7

“Onyx stones, etc.] So called from their likeness to the nail of a man’s finger: the Targum of Onkelos calls them stones of beryl; and the Targum of Jonathan gems of beryl; and the Septuagint version, stones of sardius; and some take them to be the sardonyx stones, which have a likeness both to the onyx and to the sardius: and stones to be set in the ephod, and in the breastplate; two onyx stones were set in the ephod, one of the garments of the high priest, and an onyx stone, with eleven other precious stones, were set in the breastplate of the high priest: these stones were doubtless among the jewels set in gold and silver the Israelites had of the Egyptians, and brought with them out of…”

“ephod--a square cloak, hanging down from the shoulders, and worn by priests.”

“Yahweh had redeemed the Israelites from bondage. He had made a covenant with them and had given them laws. He had promised, on condition of their obedience, to accept them as His own “peculiar treasure,” as “a kingdom of priests and an holy nation” Exodus 19:5-6. And now He was ready visibly to testify that He made his abode with them. He claimed to have a dwelling for Himself, which was to be in external form a tent of goats’ hair Exodus 19:4, to take its place among their own tents, and formed out of the same material (see Exodus 26:7 note). The special mark of His presence within the tent was to be the ark or chest containing the Ten Commandments on two tables of stone Exodus 31:18,…”

“Onyx stones: Exo 28:9-21 ephod: Exo 28:4, Exo 28:6, Exo 28:15 Exodus 25:8”