Genesis 47:20
And Joseph bought all the land of Egypt for Pharaoh; for the Egyptians sold every man his field, because the famine prevailed over them: so the land became Pharaoh’s. And Joseph bought all the land of Egypt for Pharaoh; for the Egyptians sold every man his field, because the famine prevailed over them: so the land became Pharaoh’s.
This verse belongs to the account of Egypt's severe famine and Joseph's management of food, in which his wise preparations enriched the kingdom. Because the famine prevailed severely over Egypt, the Egyptians each sold his field, and Joseph bought all the land of Egypt for Pharaoh, so the land became Pharaoh's. By contrast, the Israelites were not slaves and had not sold their land, cattle or themselves for food. Joseph's father, brothers and family were given land to live on because of his service to the kingdom, and Joseph supplied them with food without taxing them.