Wilderness experience written about the Children of Israel sets a pattern of the Christian experience. We can respond with doubt (Exo 5, 6), fear (Exo 14), complaining (Exo 15, 16), outright disobedience (Exo 16). The Jews did not benefit from the word because they didn't mix it with faith (Heb 4:2). Faith when tested brings glory to God (Jam 4:1, Rom 5:2-3, 1Pe 1:6-7). Complaining gives birth to slander (Exo 16:3). When we malign leadership we are maligning God. The divine response to their grumbling is mercy e.g. (Exo 16:4-8). Divine response: (1) Provision -- undeserved in Grace (2Ti 2:13); (2) Testing -- whether they will walk in His word (2Co 5:7, Eph 4:17, Eph 5:16, 1Ki 17:5); (3) Conditions for blessing -- they had to gather the amount they needed day by day; (4) Corrections -- (Exo 16:6-8, Jer 17:9); (6) Instruction -- (Exo 16:9-19) -- we can avail ourselves of it or not. Instruction includes the fact He's listening (Mat 12:36) but He also reveals their ignorance (Psa 106:15); the all-sufficiency of His grace (Exo 16:18); everyone gets enough to be able to pass it on (2Co 8:15); when we hoard God's blessings the supply will dry up (Exo 16:19-20). Disobedience is always visible (Heb 3:7, Heb 3:17). The test brings a response and motivates a memorial -- the sabbath rest (Exo 16:22-35). When there is no provision the purpose is to instruct, to humble, to test (Deu 8:1-4); what is going on in our lives "that He might make thee know that man doth not live by bread only, but by every word that proceeds out of the mouth of the LORD doth man live". (Heb 3:7-11). We test God while He tests us (Heb 3:9) if we do not respond appropriately, namely that we are trained for our profit (Heb 12:10-11).
After 40 years in the Egyptian palace then 40 years in the desert then 40 years leading Israel to their land Moses' life can actually teach us about living in the time we live.