The Urim and Thummim were special objects used by the ancient high priests of Israel to discover God's will. (Numbers 27:21). These two Hebrew words might mean "lights and perfections." The Urim and Thummim were probably stones or tokens similar to dice or coins that could land either upright or upside down
According to Exodus 28:30, the high priest kept these objects on or in his breastpiece. The Bible does not mention their use from the time of King Saul (1 Samuel 28:6) until the time of Ezra and Nehemiah (Ezra 2:63; Nehemiah 7:65), when they helped decide which returning priests could serve again.
In 1 Samuel 14:41, the Greek translation of the Bible preserves information that may have been lost from the Hebrew text. This verse mentions the Urim and Thummim in connection with King Saul's attempt to find out who was guilty in his army. This passage shows that the objects could answer true-false or yes-no questions. The system was probably similar to casting lots.
None of the major spiritual leaders such as Abraham, Moses, David, or the prophets ever used the Urim and Thummim to determine God's will. The New Testament does not mention them at all. The Urim and Thummim belonged to the nation of Israel during its early development, not during the time of the prophets, and certainly not after the Holy Spirit became available to all believers.