The land that God promised he would give to the descendants of Abraham and Isaac and Jacob; the land flowing with milk and honey; the land of Canaan, or Palestine. The Israelites did not take it over until after the Exodus, when they conquered the people already living there.
Note: By extension, an idyllic place or state of being that a person hopes to reach, especially one that cannot be reached except by patience and determination, is called a “Promised Land.”