Deuteronomy 8:2-5
"2 Remember how the Lord your God led you all the way in the wilderness these forty years, to humble and test you in order to know what was in your heart, whether or not you would keep his commands. 3 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. 4 Your clothes did not wear out and your feet did not swell during these forty years. 5 Know then in your heart that as a man disciplines his son, so the Lord your God disciplines you."
It seems God takes us through times of testing when we have to wait a long time for Him to fulfil His plans or promises to us, but ultimately these times teach us about our own hearts and humble us. They show us how much we need him and cannot go without His word. We become disciplined through being discipline, and become more reliant on God.
You can definitely tie this passage to Jesus' testing in the wilderness.
Jesus spends 40 days in the desert fasting, paralleled to the Israelites' 40 years of wandering in the desert. This time of testing reveals what is in Christ's heart-- showing His obedience in following God's will and words. Jesus is absolutely humble, relying fully on God despite being fully divinely powerful himself. Jesus only quotes God's own words as a sustaining protection and weapon in this battle with Satan.
Jesus fulfills God's words in V3, by showing that He does not live on bread, but by God's words that are life. He knows God provides, not himself. God, literally his father, disciplines His son! And Jesus comes out, revealed to be completely faithful to God and obedient- righteous.
The idea of discipline, a time of testing required for humility to develop and a person's true nature to be revealed. I think I often fail during these testing periods, but God is gracious still and He continues to discipline me. Hopefully one day I will be able to live in His word instead of giving in to my worldly fleeting desires-- to be overwhelmed with emotion and self pity.
The "bread" isn't just physical food but all that we find security in in this world. What we think is our life, what is valuable to us, what we think we can't live without. We hold on to these things as what will help us, save us, give us security in life. This defines our value in the time of testing, but these things will not hold up.
Only God's words withstand all testing. Only who we are in Him is eternal.
God will put us through the time of testing to reveal to us what we value in our lives and strip away our reliance on those things, so that we will be disciplined to rely on Him and His words to sustain us through the trials.
