Deuteronomy 8:2-3

8:2 Remember the whole way by which he has brought you these forty years through the desert so that he might, by humbling you, test you to see if you have it within you to keep his commandments or not. 8:3 So he humbled you by making you hungry and then feeding you with unfamiliar manna. He did this to teach you that humankind cannot live by bread alone, but also by everything that comes from the Lord’s mouth.