Genesis 47:24-26 Holman Christian Standard Bible (HCSB)
24 At harvest, you are to give a fifth of it to Pharaoh, and four-fifths will be yours as seed for the field and as food for yourselves, your households, and your dependents.”
25 And they said, “You have saved our lives. We have found favor in our lord’s eyes and will be Pharaoh’s slaves.” 26 So Joseph made it a law, still in effect today in the land of Egypt, that a fifth of the produce belongs to Pharaoh. Only the priests’ land does not belong to Pharaoh.