What is breastpiece in exodus?

In the Bible, specifically in the book of Exodus, a breastpiece is mentioned as a part of the priestly attire. It was made of gold, blue, purple, and scarlet yarns, as well as fine twisted linen. The breastpiece contained twelve precious stones, each representing one of the twelve tribes of Israel. The stones were set in four rows of three, and each stone was engraved with the name of one of the tribes.

The breastpiece was worn by the high priest as a symbol of his authority and his role as a mediator between God and the people. It was also used for divination, as the Urim and Thummim (mysterious objects) were kept inside the breastpiece. The high priest would consult God by asking a question and then reaching into the breastpiece to pull out one of the objects, which would give a yes or no answer.

The breastpiece was an important part of the priestly attire and played a significant role in the religious practices of the Israelites.