The twelve stones are to correspond to the names of the sons of Israel, each engraved like a seal with the name of one of the twelve tribes.
The breast-plate, fastened by golden chains to the ephod, holds the names of all twelve tribes before God continually. Aaron bears them as a memorial; and so our great High Priest carries His people into the very presence of God, where by faith we sit with Him in heavenly places even now.
AI summary
Commenting on Exodus 28:15-30
And thou shall make upon the breastplate chains at the ends,.... One end of them to be put to the breastplate, and the other end to the ouches on the shoulder pieces of the ephod, by which the breastplate hung from thence: the Targum of Jonathan renders it, chains of a certain determined size, of length and thickness exactly alike; or terminable ones, as it...
Exo 28:21 “And the stones shall be according to the names of the sons of Israel, twelve according to their names; seal-engraving according to each one’s name shall be for the twelve tribes.” (On אישׁ before על־שׁמו see at Gen 15:10.)