The exact process of casting lots is not presented in this passage. Some commentators reason that Aaron had two stones, one with the name Yahweh
and the other with the name scapegoat.
Others suggest that Aaron used a dice with alternating light and dark sides. Still, some authors argue that Aaron would use the Urim and Thummim to determine the function of each goat.
8 And Aaron shall cast lots over the two goats, one lot for the LORD and the other lot for Azazel.