Deuteronomy 8:3, 16

He humbled you, causing you to hunger and then feeding you with manna, which neither you nor your ancestors had known, to teach you that man does not live on bread alone but on every word that comes from the mouth of the LORD.

He gave you manna to eat in the wilderness, something your ancestors had never known, to humble and test you so that in the end it might go well with you.