Genesis 47:23-26

23Then Joseph said unto the people, Behold, I have bought you this day and your land for Pharaoh: lo, here is seed for you, and ye shall sow the land. 24And it shall come to pass at the ingatherings, that ye shall give a fifth unto Pharaoh, and four parts shall be your own, for seed of the field, and for your food, and for them of your households, and for food for your little ones. 25And they said, Thou hast saved our lives: let us find favor in the sight of my lord, and we will be Pharaoh’s servants. 26And Joseph made it a statute concerning the land of Egypt unto this day, that Pharaoh should have the fifth; only the land of the priests alone became not Pharaoh’s.