The theme of this section of the psalm is fidelity to the Lord’s law. The desire and pursuit for righteousness is expressed in the words “How can a young man keep his way pure?” (Ps 119:9). Though purity is the goal, there is a tendency to apostasy which the psalmist recognized in his heart. The tendency is to seek to be free from the law in order to seek self satisfaction.

…he realized the need to protect himself from the tendency to sin.

For example, in verse 9, he mentioned “guarding” the way of life. That which is not in danger does not require protection. Thus, he realized the need to protect himself from the tendency to sin. Also, verse 16 mentioned the intended result of taking pleasure in the Lord’s statutes is “that I might not forget your word.” This term “forget” refers back to what Moses said to Israel. He told the people, “Take care lest you forget the LORD your God by not keeping his commandments and his rules and his statutes” (Deut. 8:11). The idea is not just forgetting, but forgetting which results in apostasy.

Apostasy is a sober topic, so the psalmist deliberately and soberly resolved to “guard” himself from forgetting. This tendency to wander from God’s will, and ultimately forsake the way of righteousness, is in all men. Therefore, recognizing this in himself, the psalmist sought a plan to remain faithful to his God.

This plan involved several practices which have various results. In verse 11, for example, he resolved to memorize His words, so he would not sin against the Lord. In verse 13 he resolved to read the word aloud (literally: “record with my lips”) and meditate on the word in order that he would perceive the ways in which God would have him walk.

This psalm puts words in the mouth of the reader. The verbs are in the first person singular (I, me, my). It is a pledge and prayer to God, and a plea for help. It should be read as such. Nevertheless there is some difficulty which comes from the nature of having words placed in one’s mouth. One may not agree with everything. The law is often met with opposition. The nature of this work is that it is introspective and humbling. It takes courage to seek satisfaction in God’s will. It takes discipline. The sternness of the law ultimately leads one to seek that great and glorious redemptive promise that Jesus died for his people, while even still sinners.

In this way, this psalm has an implicit call to continued penitence, but also a resolved faith in the testimony of Christ. We must continue to believe those promises of redemption and peace because it is not we who guard ourselves, but God who guards us. The psalmist these Gospel promises valued as one would value all wealth (v 14). Turn to the Father to confess your sins, in the name of the one who pardoned you by his substitution on your behalf.