Psalms 37:31

The wicked watcheth the righteous,.... All his motions and steps, his works and actions; he watches for his halting, and to take all opportunities and advantages against him; see Jer 20:10;

and…

The law of his God is in his heart - That is, he loves it; he thinks of it; he makes it the inward rule of his conduct: Deu 6:6; Psa 40:8 The word “law” here is a general term for the truth of God -…

These verses are much to the same purport with the foregoing verses of this psalm, for it is a subject worthy to be dwelt upon. Observe here,

I. What is required of us as the way to our happiness,…

Cp. Psa 119:11. God's law, treasured in his heart, regulates all his conduct. Without wavering or variation he pursues the path of right. Cp. Psa 26:1; Psa 73:2.