The urim v’tumim was a parchment upon which was written the Shem Ha’Meforash, Hashem’s Ineffable Name. Only when Moshe placed the choshen on Aharon were the urim v’tumim inserted in the choshen. This procedure seems strange. Would it not have been more convenient to simply place the parchment with the Name into the choshen before the Kohen Gadol put it on?
Horav Dovid Feinstein, Shlita, derives an important lesson from this process. The choshen symbolizes fairness and integrity in financial dealings, which is why it was called the choshen ha’mishpat, breastplate of justice. This choshen was attached to the ephod, which represents avodah, service to Hashem. The bond between the choshen, symbol of justice, and the ephod, symbol of service to Hashem, indicates that true justice can exist only if it is integrated with Hashem’s will and inspired by His guidance.
Consequently, it was first imperative to attach the symbol of justice, the choshen, to the ephod, the symbol of service, in order to affirm Am Yisrael’s commitment to G-d given justice. Veracity is the foundation of justice.
Only after this bond existed could the choshen become a suitable setting for Hashem’s Name. The connection provided the essential power with which to bring Hashem’s justice into this world. If the urim v’tumim were to be placed on the choshen prior to being attached to the ephod, it would seem to sanction justice without Hashem’s will.
Veracity is an integral aspect of godliness. As a godly people, Bnei Yisrael are mandated to be a truthful people, an image which they must uphold for the world to see and replicate.