Our fathers understood not Thy wonders in Egypt; they remembered not the multitude of Thy mercies… – Psalm 106:7

The wonders that God wrought in Egypt were exceedingly great and instructive. The ten plagues were memorable master-strokes of God’s judgment upon the proud, and notable displays of His favor to the oppressed. How Egypt staggered beneath the blows of Jehovah! Those tremendous judgments came one after another with righteous deliberation, and yet with terrible rapidity. Pharaoh and his proud nobles were wounded and humbled: the leviathan of Egypt was broken in pieces as one that is slain. Surely, they for whom all these plagues were wrought ought to have considered them, and ought to have spied out the plain lessons which they taught; but they failed to do so, for they were dull of understanding. Albeit, God had come out of His secret places, and had made bare His arm for them, yet “our fathers understood not Thy wonders in Egypt.”

How wretchedly have we complained when God, in His gracious dealings with us, has caused us an inward grief! He began to show us our sin—a very necessary thing; but we kicked against it and said, “Is this the grace of God? Oh, that we were rid of these convictions!”…How else should we feel our need of redemption and be willing to come forth free by the blood of the Lamb?…Our fathers understood not His wonders in Egypt, and oftentimes this is our case; we judge by the feelings of the present, and forget the eternal future. We cannot understand our burdens and our soul-humblings; we stand bewildered and amazed. Though the point is plain enough to faith, unbelief does not hear the rod, nor Him that has appointed it; but we are taken up with our present smart. Our selfish desire for immediate comfort prevents our understanding the great plans of divine grace. ~ C.H. Spurgeon

https://www.blueletterbible.org/comm/spurgeon_charles/sermons/2204.cfm