Deuteronomy 18:3-5

Living Bible

³ The shoulder, the cheeks, and the stomach of every ox or sheep brought for sacrifice must be given to the priests. ⁴ In addition, the priests shall receive the harvest samples brought in thanksgiving to the Lord—the first of the grain, the new wine, the olive oil, and of the fleece at shearing time. ⁵ For the Lord your God has chosen the tribe of Levi, of all the tribes, to minister to the Lord from generation to generation.