Deuteronomy 8: 3-5
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.
Jesus quoted this verse in response to Satan's tempting. This manna was not anything this Earth produces. God sent it miraculously to the Hebrews in the Desert (Matthew 4:4). Psalm 78:23-25 tells us that this was "the grain of Heaven; men ate the bread of Angels."
Moses also ate this manna. He tells the people that God sent it to teach them that life comes not from what we eat, but from what comes from the mouth of God, His Word, which is Spirit.
Your clothes did not wear out and your feet did not swell during these forty years.
I'll bet that the people didn't even notice this detail: they wore the same clothes every year, and their sandals didn't wear out for forty years! Same old, same old, never needed replacing.
Know then in your heart that as a man disciplines his son, so the Lord your God disciplines you.
Feeding them, not letting their clothes wear out; this is discipline? We think of discipline as more or less punishment, but this sounds more like the academic definition, which is, Teaching.
Observe the commands of the Lord your God, walking in His ways and revering Him.
The conclusion here is for them to learn to apply God's commands in their lives and thinking processes, and to consider only God to be deserving of reverence, adoration, and worship. He alone is God. He alone is our Source. He loves us with a love that is deeper, wider, longer, higher than any other imaginable love. That's why He is the only one who merits our honor and obedience.
And when we obey His ways, we will receive the effects--the benefits of what He's built into this World system. And he gets all the glory.
Even so, come, Lord Jesus!
