Charles H. Spurgeon on Psalms 119:18

Wondrous things. Many were the signs and miracles which God wrought in the midst of the people of Israel, which they did not understand. What was the reason? Moses tells us expressly what if was: "Yet the Lord hath not given you an heart to perceive and eyes to see, and ears to hear, unto this day" (Deuteronomy 29:4). They had sensitive eyes and ears, yea, they had a rational heart or mind; but they wanted a spiritual ear to hear, a spiritual heart or mind to apprehend and improve those wonderful works of God; and these they had not, because God had not given them such eyes, ears, and hearts. Wonders without grace cannot open the eyes fully; but grace without wonders can. And as man hath not an eye to see the wonderful works of God spiritually, until it is given; so, much less hath he an eye to see the wonders of the word of God till it be given him from above; and therefore David prays, Open thou mine eyes, that I may behold wondrous things out of thy law. And if the wondrous things of the law are not much seen till God give an eye, then much less are the wondrous things of the Gospel. The light of nature shows us somewhat of the Law; but nothing of the Gospel was ever seen by the light of nature. Many who have seen and admired some excellencies in the Law could never see, and therefore have derided, that which is the excellency of the Gospel, till God had opened their heart to understand. Joseph Caryl, 1602-1673.