Think for a moment about all the ways God has met the needs of His people throughout history.
When Israel was in the wilderness, they had no supermarkets or grocery stores. There was not even a blade of grass in sight. But God rained down manna from heaven so the people would have bread, and He caused birds to fall by the bushel from the sky so they would have meat. He caused water to gush from a rock. And He supernaturally kept their shoes and clothing intact, so that they never wore out in forty years of use.
In the Old Testament, we read that a hungry prophet was fed by a raven. A barrel of meal and a bottle of oil supernaturally replenished themselves. And an entire enemy army fled upon hearing a strange noise—leaving behind enough supplies to feed an entire city of starving Israelites.
In the New Testament, we read that water was turned into wine. Money was found in a fish's mouth to pay taxes. And five thousand people were fed with only five loaves of bread and two fish.
All these miracles of supply cry out to us, "God is faithful. He can be trusted!" And in Leviticus 25, we read of another supernatural phenomenon—an especially ripe harvest in the year before the sabbath for the land.
Next, God commanded that the people observe seven consecutive cycles of sabbaths for the land: "Thou shalt number seven sabbaths of years unto thee, seven times seven years; and the space of the seven sabbaths of years shall be unto thee forty and nine years" (verse 8). In other words: "You are to celebrate this sabbath every seventh year, for a period of forty-nine years—seven sabbaths times seven."
In biblical terms, the forty-nine-year period would comprise a whole generation. The implication here is that such a period would provide enough time for an entire generation to learn to trust the Lord. Over that time, parents and grandparents would build up a history of faith, so they could tell their children: "Yes, it's true! God supplied everything we needed the first six years, but when the seventh year came, many of us were afraid. Yet God's provision saw us through to the eighth year, and right up to the ninth. Sometimes it was frightening, but there was always enough. No one starved, and no one had to beg. Every need was supplied. God tested our faith—and He remained faithful!"
The point is, when God says, "Trust me," He means it!