Genesis 47:19
Wherefore shall we die before thine eyes, both we and our land? buy us and our land for bread, and we and our land will be servants unto Pharaoh: and give us seed, that we may live, and not die, that the land be not desolate. Wherefore shall we die before thine eyes, both we and our land? buy us and our land for bread, and we and our land will be servants unto Pharaoh: and give us seed, that we may live, and not die, that the land be not desolate.
The plea was made in the time of severe famine when other lands were perishing while Egypt still had food, so that people from Canaan had to travel to Egypt to buy grain. Egypt was abundantly supplied at that time through Joseph's wise management, which enriched the kingdom.
The Egyptians asked Joseph to buy them and their land for bread so that they and their land would not die or lie desolate, thereby surrendering themselves and their property to Pharaoh in exchange for food. Israel's family did not make this surrender, but were given land to live on because of Joseph's service and were supplied with food without tax.