Read Genesis 47:26 Using Other Translations
And Joseph made it a law over the land of Egypt unto this day, that Pharaoh should have the fifth part; except the land of the priests only, which became not Pharaoh's.
So Joseph made it a statute concerning the land of Egypt, and it stands to this day, that Pharaoh should have the fifth; the land of the priests alone did not become Pharaoh's.
Joseph then issued a decree still in effect in the land of Egypt, that Pharaoh should receive one-fifth of all the crops grown on his land. Only the land belonging to the priests was not given to Pharaoh.