Comentario citado sobre Números 27:21

It is the same whether one [while impure] enters the Temple court or the addition to the Temple court, for additions are not made to the city [of Jerusalem], or to the Temple courts except by the king, prophet, Urim and Thummim, the Sanhedrin of seventy one, and with two [loaves] of thanksgiving, and with song. And the court walks in a procession, the two [loaves] of thanksgiving [being carried] after them, and all Israel [following] behind them. The inner one is eaten, and the outer one is burnt. And as to any addition that was made without all these he who enters it [while impure] is not liable. A person who is impure and enters the Temple is obligated to bring a sliding scale sacrifice even if he only entered an addition that had been made to the Temple court. In other words, the holiness inherent to the Temple is also to be found in any additions made to the Temple. The reason is that the additions made to the Temple are made with the consent of all of the ruling institutions in Israel, as well being performed in a religious ceremony. Additions to the Temple or to the city of Jerusalem, which is also considered to be holy, can only be made with the consent of the following parties: 1) the king; 2) the Urim and Thummim, the two stones that sat in the high priest’s breastplate which were used to receive oracles (see Numbers 27:21); 3) the Sanhedrin of 71 elders. The additions to the Temple would be made in a great procession with two loaves of thanksgiving. Any addition to the Temple that was not made using all of these elements was considered to be of a lower status. Therefore, one who entered there while impure would not have to bring a sliding scale sacrifice. This mishnah has some interesting historical implications. In the Second Temple period, which began in the 5th century B.C.E. and continued until the destruction of the Temple in 70 C.E. there were no Urim and Thummim. Therefore, any additions to the Temple would not have been of the same holiness. On the other hand, the mishnah does not completely delegitimize these additions to the Temple. The last clause in the mishnah indeed admits that additions to the Temple can be made without the approval of the all of these parties. The only consequence is that one who entered there impure would not be obligated to bring a sacrifice.

אלא למלך וכו' – as it is written (Numbers 27:21): “But he shall present himself to Eleazar the priest, [who shall on his behalf seek the decision of the Urim before the LORD]…” “He” is the king, “and all of the Israelites that are with him” all of the children of Israel that are with him go out to war. After him, that is the priest anointed as the chaplain of the army [that is] all of the needs of the community are upon him. “the whole community” – this is the Great Sanhedrin.

כאשר צוה ה' את משה, a reference to the fact that political decisions such as expansionary wars needed G’d’s confirmation, which was to be obtained by means of the urim vetumim in the breastplate of the High Priest, i.e. Eleazar, son of Aaron. We were told this in Numbers 27,21 when Joshua was appointed Moses’ successor. [This was an example of Joshua’s inferiority as a leader compared to Moses, who never had to resort to such indirect methods of receiving a message from G’d. Ed.]

את האורים ואת התמים THE URIM AND THE THUMMIM — This was an inscription of the Proper Name of God which was placed between the folds (i. e. the two pieces forming the front and back) of the breast-plate through which it (the breast-plate) made its statements clear (lit., illuminated its words; מאיר from אור, light, this being an allusion to the אורים) and its promises true (מתמם from the root תמם, an allusion to תמים) (Yoma 73b). In the second Temple there was certainly the breast-plate (although other objects employed in the Temple Service were missing) for it was impossible that the High Priest should have lacked a garment, but that Divine Name was not within it. It was on account of the inscription which constituted the Urim and Thummim and which enabled it to give decisions that it was called “judgment”, as it is said, (Numbers 27:21) “And he shall enquire for him by the judgment of the Urim” (Numbers 27:21).