The only land he did not buy was the land belonging to the priests. They received an allotment of food directly from Pharaoh, so they didn’t need to sell their land.
Then when you harvest it, one-fifth of your crop will belong to Pharaoh. You may keep the remaining four-fifths as seed for your fields and as food for you, your households, and your little ones.”
“The rain and snow come down from the heavens and stay on the ground to water the earth. They cause the grain to grow, producing seed for the farmer and bread for the hungry.
For God is the one who provides seed for the farmer and then bread to eat. In the same way, he will provide and increase your resources and then produce a great harvest of generosity in you.