Deuteronomy 8:3

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.

Exodus 16:15

16:15 When the Israelites saw it, they said to one another, “What is it?” because they did not know what it was. Moses said to them, “It is the bread that the Lord has given you for food.