Moses and Aaron stood before the entire assembly of Israel in the wilderness and made a promise that must have sounded almost too good to believe: "In the evening you will know that the Lord brought you out of the land of Egypt" (Exodus 16:6). The Mekhilta explains what they meant by this. While you are sleeping in your beds, the Holy One Blessed be He will provide for you.
The context is the crisis of hunger. Israel had left Egypt, crossed the Red Sea, and now faced the terrifying reality that freedom came without a food supply. They complained bitterly. They accused Moses of bringing them into the desert to starve. And Moses' response was not a logistical plan or a rationing system. It was a theological statement: God will feed you while you sleep.
The promise was fulfilled the very next morning, when Israel woke to find the ground covered with manna, the miraculous bread from heaven. The Mekhilta emphasizes the timing: evening, then morning. The provision arrived during the hours of darkness, when human effort is impossible, when no one is working or planning or strategizing. That was the point. God wanted Israel to understand that their survival did not depend on their own labor. It depended on divine grace that operated even, especially, when they were unconscious and helpless. The manna was not just food. It was a nightly lesson in trust, delivered fresh to their doorstep before they opened their eyes.