Exodus 28:15

“And thou shall make the breastplate of judgment, etc.] Called a “breastplate”, because worn upon the breast of the high priest; and a breastplate “of judgment”, because it was to put him in mind that he should do justice and judgment in the execution of his office, and that he should have at heart the judgment of the people of Israel; and in difficult cases should ask it of God, and faithfully declare it to them: it was, with the twelve stones in it, an emblem of the church and people of God, borne upon the heart of Christ our great High Priest, who are made righteous by him, yea, the righteousness of God in him, and are called by his name, the Lord our righteousness; the judgment or…”

“thou shalt make the breastplate of judgment with cunning work--a very splendid and richly embroidered piece of brocade, a span square, and doubled, to enable it the better to bear the weight of the precious stones in it. There were twelve different stones, containing each the name of a tribe, and arranged in four rows, three in each. The Israelites had acquired a knowledge of the lapidary's art in Egypt, and the amount of their skill in cutting, polishing, and setting precious stones, may be judged of by the diamond forming one of the engraved ornaments on this breastplate. A ring was attached to each corner, through which the golden chains were passed to fasten this brilliant piece of…”

“(Compare Exodus 39:1-31.) Moses is now commanded to commit all that pertains to the offerings made to the Lord in the sanctuary to the exclusive charge of the members of a single family, who were to hold their office from generation to generation. In the patriarchal times, the external rites of worship had generally been conducted by the head of the tribe or family, in accordance with the principle involved in the dedication of the firstborn Exodus 13:2; Numbers 3:12-13. Moses, as the divinely-appointed and acknowledged leader of the nation, had, on a special occasion, appointed those who were to offer sacrifice, and had himself sprinkled the consecrating blood of the victims on the people…”

“The most considerable of the ornaments of the high priest was this breast - plate, a rich piece of cloth curiously wrought with gold and purple, two spans long, and a span broad; so that, being doubled, it was a span square. In this breast - plate, the tribes of Israel were recommended to God's favour in twelve precious stones. Some question whether Levi had a precious stone with his name on or no; if not Ephraim and Manasseh were reckoned distinct, as Jacob had said they should be, and the high priest himself being head of the tribe of Levi, sufficiently represented that tribe. Aaron was to bear their names for a memorial before the Lord continually, being ordained for men, to represent…”

“28:15-30 More attention is given to the chestpiece than to any other item, suggesting the importance attached to it. It apparently symbolized the priest’s representation of Israel (28:17-21, 29) and was a container for the Urim and Thummim, by which God made his will known (28:30). The chestpiece represented the totality of the high priest’s tasks of bringing the people to God and bringing God’s word to the people.”

“the breastplate: Exo 28:4, Exo 28:30, Exo 39:8; Lev 8:8 after: Exo 28:6, Exo 26:1 Exodus 28:17”

“The second ornament consisted of the choshen or breastplate. Chosen mishpat, λογειο͂ν τῶν κρίσεωον (lxx), rationale judicii (Vulg.). חשׁן probably signifies an ornament (Arab. pulcher fuit; Ges.); and the appended word mishpat, right, decision of right, points to its purpose (see at Exo 28:30). This breastplate was to be a woven fabric of the same material and the same kind of work as the ephod. "Foured shall it be, doubled (laid together), a span (half a cubit) its length, and a span its breadth." The woven cloth was to be laid together double like a kind of pocket, of the length and breadth of half a cubit, i.e., the quarter of a square cubit. Exodus 28:17”