The lost meaning of ‘urim and thummim’: mysterious oracle of the Old Testament

From ancient astronauts to priestly divinatory practices and the Holy Grail — many theories try to explain the origin of these puzzling relics of the Israelites

Nobody knows exactly what the Ancient Hebrew urim and thummim were — the Bible does not tell us — or how they were used, or even if they were one or more objects.

Throughout history, there have been many theories about these mysterious, apparently material, items connected with the breastplate, or ephod, worn exclusively by Israelite high priests. They seem to have been stones, or a stone, used as a kind of divine oracle associated with divination and, perhaps in particular, cleromancy, the casting of lots; most scholars believe the urim and thummim (UT henceforth, excluding quotations) to have been objects associated with such divination, to the effect that academic discussion about them has largely ceased.

However, speculation in the wider sphere, both fascinating and fanciful, about these puzzling relics of ancient Israelite religious life, these fabulous ‘seer stones’, has continued. It includes their provenance in Ancient Egypt, and that they were the origin of the Holy Grail legends; they have been linked with ‘ancient astronauts’ and theories of advanced technologies existing in the far distant past; their lore has been espoused by the Mormon Church whose founder and prophet Joseph Smith is said to have consulted them; and there have even been people in recent times who claimed to possess them.

These are all issues we encounter in the strange story of the UT, along with the work of the Dutch author Cornelis Van Dam whose 1997 book on the UT was the first exhaustive study for more than 170 years, and remains the key scholarly text in the field.

We start, then, with the high priest’s ephod which was made of linen, and distinguished him from ordinary priests and lower clerics. It was tied round the neck with golden chains, covered the whole chest, and was decorated with 12 shiny gem-stones, set in gold, and bearing the names of the 12 tribes of Israel. Evidently, the UT were quite separate from these 12 stones and were kept in a square inside pocket or pouch of the ephod, so that the high priest could wear them against his chest whenever he entered the temple.

Classical texts maintain they were two sacred stones of onyx used to give an affirmative or negative response to…