He will take care of you

He humbled you, causing you to hunger and then feeding you with manna, which neither you nor your fathers 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.Deuteronomy 8:3

How does providing manna show that people should live on every word that comes from the mouth of the Lord? Is this manna God's Word? No, but God uses this example to explain what he said about hunger: "He humbled you, causing you to hunger and then feeding you with manna." He did this to show you that even if you don't have manna, God's Word can keep you alive. God's Word promises that he will never leave you and he will always take care of you. For even in times of hunger, faith in what God says nourishes, not only the soul, but also the body—the whole person. God will never abandon you. In his own time, he will provide food for your body the same way he used ravens and the widow of Zarephath to feed Elijah, and manna to feed the Israelites.

When Moses says that a person can't live on bread alone, he isn't only talking about manna. These words apply both to times when you're hungry and to times when you have plenty of food. The point is that God wants to show you his goodness through all your experiences. When you're hungry, you should learn to trust God's Word. God promises to take care of you and not let you die of hunger. When you trust in him, he will provide nourishment to your body because of your faith. He does all this to prevent you from worshiping your appetites and to teach you that life doesn't depend on a full stomach. God sustains both the body and the soul. You never would have learned this truth if your stomach had always been full. This is how you learn to trust in God.