 For the high priest these include a priestly tunic, linen undergarments, sash, robe, priestly turban, ephod (with Urim and Thummim), and a priestly breastplate with 12 stones representing the twelve tribes of Israel.The priests served in rotating priestly divisions.The starting point of much critical scholarship of the priesthood in ancient Israel is the thesis of Julius Wellhausen that Israel's history is redacted and represents three stages; (1) non Levitical priests, (2) Levitical priests, (3) Aaronids and Levites.