This is one of the earliest references to the parallel between physical and spiritual eating. It is not directly stated but implied. God intended Israel's experiences in the wilderness to instruct the Israelites that all of life, both physical and spiritual aspects, depends upon God's providence. These verses also confirm that leading a good life, an abundant life, is dependent upon one's spiritual, mental, and emotional base. These elements of the mind determine one's outlook, goals, and reactions to the myriad vicissitudes of life. These verses confirm that God directly leads us into many of them, as a means of instructing us, producing dual results: first, to experience them and develop certain characteristics; second, to test us so both He and we can see where we stand and how we cope.
A major problem is that human nature compels us to focus almost totally upon the physical. God provides us "wilderness experiences" to let us know that there is a spiritual aspect to life that requires feeding and maintenance just as surely as the physical. Prayer, study, meditation, and obedience are the assimilation process in this parallel. Within this feeding/assimilation process, our relationship with God, worship, and religion should be enhanced to play an effective, positive role in life. Worship is more than adoration and reverence; it is the response of the whole person to the entirety of God's will in all aspects of life. In the church, at home, on the job, and in the community, our direction must always be whatever God wills.
Starvation of the spirit is less obvious on the outside than physical hunger because the spirit starves much more slowly and it resides within. Spiritual malnutrition may go unrecognized for long periods because the body and life goes right on. Yet just as surely as one's body gives signs that it needs nourishment, so does the spirit, and it, too, will eventually be recognized on the outside by its symptoms.
When the body cries out for food, one feels emptiness in the stomach, weakness in the muscles, and even sleepiness. If it goes on long enough, a faintness and headache may arise. But when the spirit is malnourished either from deprivation or a harmful diet, the gradual reaction in life is different.
Spiritual weakness appears, as does sin. With sin comes anger, irritability, exasperation, depression, discouragement, melancholy, despondency, gloominess, bitterness, hatred, resentment, self-pity, hopelessness, despair, paranoia, envy, jealousy, family conflict, arguing, divorce, drunkenness or other addictions, and competitiveness as self-centeredness deepens.
A purpose of Deuteronomy 8:2-3 is to emphasize to Israel and now to us that the source of spiritual nourishment is more important than the nourishment itself. If we have the right source, the nourishment will be good. Otherwise, the situation is hopeless. Our source of nourishment must, of course, be God.
When tempted by Satan, Jesus quotes this verse (Matthew 4:4). He suggests in His answer that, unlike Esau, He received a vitality that sustained Him even though He had not physically eaten. Therefore, He had no need to succumb to Satan's temptation. Israel also demanded bread in the wilderness. They ate and proceeded to die there. Jesus denied Himself bread, instead trusting God in submission to Him, retained His righteousness, and lived.