Then he put the breastpiece on him and placed the Urim and Thummim in the breastpiece.
God had given Moses orders to consecrate Aaron and his sons to the priests' office, when he was with him the first time upon mount Sinai, Ex. 28 and Exo 29:1, where we have also the particular instructions he had how to do it. Now here we have, I. The orders repeated. What was there commanded to be done is here commanded to be done now, Lev 8:2, Lev 8:3.
Commenting on Leviticus 8:1-13
And he put the breastplate upon him,.... Which was made of the same materials with the ephod, and was put upon it, and fastened to it: also he put in the breastplate the Urim and Thummim: that is, Moses did it, as all the rest; for there is no reason to be given why this should be appropriated to God as a divine work, distinct...
He put in the breastplate the Urim and the Thummim - The Urim and Thummim are here supposed to be something different from the breastplate itself. See Clarke's note on Exo 28:15, See Clarke's note on Exo 28:16, See Clarke's note on Exo 28:30.