Exodus 28:30

“And thou shall put in the breastplate of judgment the Urim and the Thummim, etc.] What these interpreters are at a loss about, both Jewish and Christian; some have confessed their ignorance of them, have conjectured they were only these two words and put in the duplicature of the breastplate; that the name of Jehovah, with other divine were put there and so called; and some have that they were little images, the same with the teraphim, the high priest carried in the folds of breastplate, by which consultation was made; others have thought them to be a work purely divine, of Jehovah’s putting there; for my own part I am to follow Josephus f840, who takes them to be the same with the twelve…”

“thou shalt put in the breastplate of judgment the Urim and Thummim--The words signify "lights" and "perfections"; and nothing more is meant than the precious stones of the breastplate already described (compare Exo 39:8-21; Lev 8:8). They received the name because the bearing of them qualified the high priest to consult the divine oracle on all public or national emergencies, by going into the holy place--standing close before the veil and putting his hand upon the Urim and Thummim, he conveyed a petition from the people and asked counsel of God, who, as the Sovereign of Israel, gave response from the midst of His glory. Little, however, is known about them. But it may be remarked that…”

“(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 Urim and Thummim - By which the will of God was made known in doubtful cases, was put in this breast - plate, which is therefore called the breast - plate of judgment. Urim and Thummim signify light and integrity: many conjectures there are among the learned what they were: we have no reason to think they were any thing that Moses was to make, more than what was before ordered; so that either God made them himself, and gave them to Moses, for him to put into the breast - plate when other things were prepared; or, no more is meant but a declaration of the farther use of what was already ordered to be made. The words may be read thus, And thou shalt give, or add, to the breast - plate of…”

“28:30 The Urim and Thummim (Hebrew terms that might translate as lights [or curses] and perfections) were apparently a pair of stones that were thrown down to get a yes or no answer from God. No physical description of these objects exists; their use is further explained in Num 27:21; Deut 33:8; 1 Sam 28:6; Ezra 2:63; and Neh 7:65.”

“the Urim and Thummim, את אורים ואת התמים the Urim and Thummim, lights and perfections; rendered by the LXX δηλωσιϚ και αληθεια, manifestation and truth; and, by the Vulgate, doctrina et veritas, doctrine and truth. Among the various and contradictory opinions respecting the form and substance of these mysterious appendages, the most probable seems to be that of Josephus, Philo, Bp. Patrick, Parkhurst, and the Jewish writers generally; who state, that they were no other than the twelve precious stones of the high priest's breastplate. In support of this statement, it is observed: 1\. That in the description of the high priest's breastplate, Exo 39:8, et seq., the Urim and Thummim are not…”

“Into this choshen Moses was to put the Urim and Thummim, that they might be upon his heart when he came before Jehovah, and that he might thus constantly bear the right (mishpat) of the children of Israel upon his heart before Jehovah. It is evident at once from this, that the Urim and Thummim were to bring the right of the children of Israel before the Lord, and that the breastplate was called choshen mishpat because the Urim and Thummim were in it. Moreover it also follows from the expression אל נתתּ, both here and in Lev 8:8, that the Urim and Thummim were not only distinct from the choshen, but were placed in it, and not merely suspended upon it, as Knobel supposes. For although the lxx…”