The Ramban brings Rashi and explains that the Urim V’Tumim was the Shem HaMiforash, and it was placed into the folds of the Choshen. The Choshen needed to be doubled, in order to be able to place the Shem HaMiforash inside. The Ramban points out that throughout the Parshiyos of the command to build the Mishkon and in all its building, there is no command to make the Urim v’Tumim nor does it talk about their making whatsoever. By the Eifod it states, “and they shall make the Eifod” “and he made the Eifod,” and about the Choshen it states, “and you shall make the Choshen” “and he made the Choshen.” Whereas by the Urim V’Tumim it does not mention “and you shall make the Urim V’Tumim” nor “and he made the Urim v’Tumim.” Had it been work of a carpenter or craftsman, the Torah would’ve certainly mentioned its construction with detail. No craftsman was involved nor did anyone from Klal Yisrael give contributions for it nor were involved in its making. It was a secret given over to Moshe from the mouth of Hashem, and either he wrote it with holiness or it was created by the actions of Hashem. Therefore, the Torah mentions the Urim V’Tumim in general as though they are something known, not part of our making.
The function of the Urim V’Tumim was to respond to questions raised, and it would reveal future occurrences that would become known by Hashem’s message through the Urim V’Tumim. The Ramban says that it was on the level of ruach haKodesh, and was beneath prophecy, and above a bas kol which was used during the 2nd Bais HaMikdash.
The Drashos HaRan says that the Urim V’Tumim was not included in the eight garments of the Kohen Gadol. During the 2nd Bais HaMikdash, there was no Urim V’Tumim, and, yet, the Kohen Gadol did avodah with the eight garments. We see that the Urim V’Tumim was something extra, it was in addition to the eight garments. He proves this, since the Urim V’Tumim’s making is not mentioned in Parshas Pekudei where it mentions “ויעש את החשן.” It does not state “ויעש את האורים ותומים.” The reason is because it wasn’t made by craftsmen whatsoever; rather Moshe alone was commanded about it, “and you shall put into the Choshen HaMishpat, the Urim V’Tumim.”
The Drashos HaRan points out that the Urim V’Tumim wasn’t something fitting to come to Aharon’s portion, rather to a prophet who would prophesize. Just as a prophet’s job was prophecy and not avodah, so too, a Kohen’s job was avodah and not prophecy. Since the Urim V’Tumim is not included in the garments of Kehuna, and it has to do with prophecy which is fitting for a prophet, why did Aharon merit to be given the Urim V’Tumim?
The Drashos HaRan answers that Aharon merited to be given the Urim V’Tumim because he was not jealous of Moshe who became the prophet of Klal Yisrael. Although Aharon was older than Moshe, and Aharon even prophesized before Moshe did, Aharon had no jealousy whatsoever. In the same thing that he showed his good, favorable heart, he merited to receive reward. He was given the Urim V’Tumim to be able to tell over the future occurrence, which is at least equivalent to prophecy, although it wasn’t fitting for the inyanim of Kehuna. The Gemara brings that although a decree from a prophet could be overturned, a decree of the Urim V’Tumim is never overturned. If so, Aharon merited an even higher level than the level of prophecy. Also, he merited this for himself and for his offspring, whereas Moshe did not. This was all because, Aharon who was involved with Moshe Rabeinu to take Klal Yisrael out of Mitzrayim was not jealous of Moshe the entire time!
Let us learn from Aharon to get rid of our jealousy, and be happy for another person’s good attribute!