Levi, though one of the sons of Israel, is usually omitted from Biblical passages listing the tribes of Israel. The descendants of Levi were consecrated as priests to God and were responsible for the service of the tabernacle in the wilderness and later with the temple in Jerusalem. Instead of receiving land as an inheritance in Palestine, the Levites received tithes and offerings from the children of Israel (Numbers 18, Deuteronomy 18, etc.).
Although Joseph was also one of Jacob's sons, he too is usually omitted from lists of
the tribes of Israel. This is because the two sons of Joseph,
Ephraim and Manasseh, were adopted by Jacob in Joseph's stead (Genesis 48).
