I sometimes feel like the Hebrews of the Exodus are the characters in a horror film. When watching a 'slasher movie' I want to yell at the screen' "don't go into the basement", but despite my warnings the character always does. Reading Numbers, I want to yell at my Bible, "trust the Lord", but the Hebrews don't, or didn't.
At this point they have been out of Egypt a little over a year. They left right after the first Passover. It took a month or so to get to Mount Sinai. They waited for Moses for 40 days (twice). They built all the Tabernacle stuff and finished up about the time of the second Passover. This entire time they ate the 'daily bread' and should have learned to trust the Lord on a small, personal, daily or routine level. That should have complemented the 'Trust the Lord' lessons on the big things like the Plagues, the guiding pillar of fire/smoke, and the Red Sea (including the destruction of the Egyptian army).
I suppose the daily miracle of mana could become routine and overlooked, even boring after a year. The delivery of the quail should have been a welcome surprise miracle. Just having enough water to keep them all alive is amazing to me. I wonder what daily miracles I may be overlooking.
Then we see the open rebellion against Moses even by those that should know better, Aaron and Miriam. I'm sure there was widespread discontentment because everyone (including me) thinks things would work better if they were running the show. This is a lack of trust in God's appointed liaison with Him and in God's leadership.
The 'kicker' though is the fear generated by the spy's report of the son's of Anak. The Anakim were "giants" although we are not quite sure what that means (They seem to be one clan of the Rephaites who are vaguely tied to the Nephilim of Genesis 6). After all the miracles to this point, I wonder why the report of the spies started a wave of fearful panic strong enough to abandon the Lord. Hey you ancient Hebrews, don't go into the basement!