Deuteronomy 8:3 (ESV) … “And he humbled you and let you hunger and fed you with manna, which you did not know, nor did your fathers know, that he might make you know that man does not live by bread alone, but man lives by every word that comes from the mouth of the Lord.”
Moses says it was a time of humbling: “And you shall remember the whole way that the Lord your God has led you these forty years in the wilderness, that he might humble you” (8:2a).
That God used the wilderness wanderings to humble them is mentioned three times in this chapter (8:2, 3, 16). The humbling is closely related to the disciplining process. Deuteronomy 8:3 explains that God “humbled [them] and let [them] hunger and fed [them] with manna.”
Discipline helps produce humility by taking away the human props of which we are sometimes proud. Then as helpless people we have to trust in God alone.
Each morning during their wilderness journey, God sent the Jewish people “angels’ food” (Ps. 78:21–25) to teach them to depend on Him for what they needed. But the manna was much more than daily physical sustenance; it was a type of the coming Messiah who is “the bread of life” (John 6:35). When Satan tempted Him to turn stones into bread (Matt. 4:1–4), Jesus quoted Deuteronomy 8:3 and indicated that the Word of God is also the bread of God; for we “feed on” Jesus Christ when we “feed on” the Word of God. God was teaching the Jews to look to Him for “daily bread” (Matt. 6:11) and to begin each day meditating on the Word of God. Those who obeyed God in the daily responsibility of gathering manna would be inclined to obey the rest of His commandments. Our relationship to the Word of God (manna) indicates our relationship to the God of the Word.
 Hughes Kent R. (2012). A Word to Those Who Preach the Word. In R. K. Hughes (Ed.), Preaching the Word: Deuteronomy—Loving Obedience to a Loving God (pp. 298–299). Wheaton, IL: Crossway.  Wiersbe, W. W. (1999). Be equipped (pp. 60–61). Colorado Springs, CO: Chariot Victor Pub.