Genesis 47:24-26 World English Bible (WEB)
24 It will happen at the harvests, that you shall give a fifth to Pharaoh, and four parts will be your own, for seed of the field, for your food, for them of your households, and for food for your little ones.”
25 They said, “You have saved our lives! Let us find favor in the sight of my lord, and we will be Pharaoh’s servants.”
26 Joseph made it a statute concerning the land of Egypt to this day, that Pharaoh should have the fifth. Only the land of the priests alone didn’t become Pharaoh’s.