God revealed Himself using the Urim and Thummim and did other things that are hard for us to believe today. God spoke from a burning bush (Exodus 3). He parted the Red Sea (Exodus 14). He made the sun stand still (Joshua 10). He allowed a donkey to talk (Numbers 22). The Urim and Thummim fade into history. They’re mentioned one last time in Nehemiah 7:65, but it’s unclear if they were ever found or used then.
I don’t know if you’ve thought much about the Urim and Thummim.
The first mention of them can be found in the book of Exodus 28. In verse 15, God tells Moses to make “make a breastpiece of judgment.” The CSB calls it “an embroidered breastpiece for making decisions.” In verse 30, we read:
And in the breastpiece of judgment you shall put the Urim and the Thummim, and they shall be on Aaron’s heart, when he goes in before the LORD. Thus Aaron shall bear the judgment of the people of Israel on his heart before the LORD regularly.
They seem to be part of the breastplate worn by the high priest of Israel. We don’t know what they looked like. Some believe they were two stones — possibly gemstones — or other objects, possibly inscribed with symbols or words. We don’t know for sure.
We also don’t know how they were used. Some think they were a form of lots, like casting dice or drawing straws. Some think that they spelled out answers. Others think that they had numbers on them, or that they had two sides, one saying “yes” and the other “no.” Others think they used colors.