Hebrews 7:6
7:5The Israelites were descendants of Jacob, who was Abraham's grandson. God gave Jacob a new name, Israel. Jacob's 12 sons became the ancestors of Israel's 12 tribes . Levi was the ancestor of the tribe of Levi. Levites who were descendants of Aaron were priests who served God in the temple . The other Levites helped the priests. See Numbers 1:50; Exodus 28:1.
