Psalm 119 is the longest psalm. It speaks repeatedly of the wisdom, guidance, comfort, correction, challenge and assurance which David receives from the Word of God.
He looks to scripture as his main teacher, trainer, moralist, therapist, encourager, protector and reward. Seemingly every verse heaps praise and thanksgiving upon God’s ‘laws, statutes, commandments, ordinances, testimonies, ways, precepts, etc’. Every verse except three.
I would suggest that in these verses one finds hidden the message not of law but of grace:
Verse 90: Thy faithfulness is unto all generations: thou hast established the earth and it abideth.
Verse 122: Be surety for thy servant for good: let not the proud oppress me.
Verse 132: Look thou upon me, and be merciful unto me, as thou usest to do unto those that love thy name.
What is being said here? God is eternally faithful. I am trusting in the Almighty Creator and not in myself to reach the finish line. He will guarantee or stand as surety for the supply of all righteousness in my life. I will be forever deficient. He will be forever sufficient. Neither oppression nor condemnation will be able to do me irreparable damage. Such a God compels me through love into obedient service. He is always fondly aware of my state and He constantly extends to me His mercy. This is the heritage of the faithful, of those who seek His face and love to consider His nature/name.
Did David realize that he was foreshadowing all of this some hundreds of years before the Gospel? The Holy Spirit did. (1 Peter 1: 10-12)