Urim and Thummim

The Urim and Thummim were placed in the breastplate of the high priest (Exodus 28:30) and were used as a means of communication with God. They mean "light" and "perfection". Unfortunately, they are not described anywhere in the Bible. Some theories maintain that they were twelve stones that made up part of the High Priest's garments. The process of the communication with God is not given either.