en_tn/lev/08/08.md

He placed the breastpiece on him

"Moses placed the breastpiece on Aaron"

the breastpiece ... the turban ... the golden plate, the holy crown

These are all special garments that Yahweh commanded the people to make for the priests. (See: rc://en/ta/man/translate/figs-explicit)

the Urim and the Thummim

It is not clear what these are. They were objects that the priest somehow used to determine the will of God. (See: rc://en/ta/man/translate/translate-unknown)