The only land he didn't buy belonged to the priests because they had a food allowance provided to them by Pharaoh, so they didn't have to sell their land.
However, when it's harvested, you have to give one-fifth of it to Pharaoh. The other four-fifths you can keep as seed for the fields and as food for you, your households, and your children.”
In the morning, sow your seed. In the evening, don't stop. For you have no way of knowing which crop will grow well—one may be profitable, or the other—or maybe both.
It's like the rain and snow that fall from heaven. They don't go back there until they've watered the earth, making plants grow and flower, providing seeds for the sower and food to eat.
For who is the trustworthy and thoughtful servant? It's the one his master puts in charge of his household to provide them with food at the proper time.