Psalms 37:31 Commentary: Law in the Heart, Steps Secure

Psalm 37 is an alphabetic acrostic wisdom psalm. Lange quotes Amyrald’s image of verses strung like pearls. The poem contrasts the fate of the righteous and the wicked, exhorting trust in God’s justice despite apparent prosperity of the wicked (vv. 1, 7, 34). Verse 31 sits within a section (vv. 27, 34) that pairs calls to “depart from evil, and do good” (v. 27) with promises of security. The law (torah) in the heart is a covenantal ideal drawn from Deuteronomy 6:6, 11:18, and 11:20, where Israel is commanded to keep God’s words in their heart. The promise that no steps will slide echoes the psalm’s earlier assertion that “a man’s steps are established by Yahweh” (37:23) and that the righteous, though they fall, are not utterly cast down (37:24). In Hebrew thought, the leb (heart) is the seat of will and understanding, not just emotion. The verb maʿad (“to slip, slide, totter”) appears in other psalms for moral or physical stumbling (17:5; 73:2). An internalized law thus governs not only the mind but the direction of one’s life, even under threat from the wicked (vv. 32, 33). The cultural context: God’s instruction was not merely a code but a comprehensive guide for every sphere of life. This verse assured believers that their stability came from God’s truth dwelling inside them, a strength beyond their own.

The consulted sources note no significant textual variants for Psalm 37:31. The wording is consistent across ancient manuscripts and translations. Keil and Delitzsch reference a similar grammatical construction in Psalms 18:35 and 73:2 (Chethîb) but not a variant here.

This verse has been used throughout church history to highlight the importance of internalizing God’s Word. Christian interpreters, from the early church fathers to Reformation commentators, have connected it with the new covenant promise of Jeremiah 31:33, God writing His law on hearts. In Reformed tradition, Calvin used the verse to argue that the righteous have a fixed inward rule that produces stability. Matthew Henry applied it to practical godliness, encouraging believers to treasure Scripture in their hearts as a guard against temptation. The verse has also been a favorite in devotional literature on Scripture memory and the role of the law in the believer’s life. The phrase “steps shall not slide” appears in hymns and poems about the security of those who walk with God.

Three-point outline

1. The Source of Stability: God’s Law in the Heart. The righteous person does not merely know the law; he loves it and makes it the inward rule of conduct. As Barnes notes, when truth is in the heart, words and actions follow (cf. Psalm 40:8).
2. The Result: Steps That Do Not Slide. The verb “slides” (timʾad) is singular with a plural subject (Keil & Delitzsch), suggesting the unity of the righteous person’s walk. This is not a promise of never falling (v. 24 allows a fall) but of final preservation and a steady, God-ordered path.
3. The Contrast: The Wicked’s Instability. While the wicked spread like a green tree (v. 35) and seem secure, they pass away suddenly. Inner lawlessness leads to outer collapse. The righteous, by contrast, have a fixed inward rule that keeps them firm.

Five-point outline

1. The Law: God’s instruction (torah) as a gift, not a burden.
2. The Heart: The center of affection and will, where the law dwells permanently.
3. The Steps: The course of daily life, every decision and action.
4. The Slide: Moral failure or ruin; the righteous are kept from final destruction.
5. The Promise: Preservation through trial, grounded in God’s faithfulness.

Illustration hooks

• A child who internalizes the rule to look both ways before crossing learns to do it automatically, even when distracted. The law becomes second nature.
• A musician who practices scales until they are in her fingers can play freely under pressure. Internalized technique supports performance.
• A driver who knows traffic laws thoroughly obeys them even on an icy road. Deep knowledge steadies the hands in a crisis.

Questions your congregation is asking

• “If the law is in my heart, why do I still sin and stumble?”
• “How can I get God’s law into my heart? Is it just memorization?”
• “Does this promise guarantee that nothing bad will ever happen to me?”

Psalm 37:31 presents a profound connection between our inner life and outward stability. As you discuss, consider what it means to have God’s law not just known but loved and internalized.

Discussion questions

1. Observation: According to verse 31, where is the law of God located in the righteous person? What does “heart” signify in Hebrew thought?
2. Observation: What result follows from having the law in the heart? How are “steps” and “slide” used elsewhere in the Psalms (e.g., 17:5; 73:2)?
3. Interpretation: How does the law in the heart keep the steps from sliding? What is the relationship between inner devotion and outward conduct?
4. Interpretation: Compare verse 31 with verse 24: “Though he fall, he shall not be utterly cast down.” Do these verses teach different things about the righteous person’s stability, or do they complement each other?
5. Application: What practices help you internalize God’s Word so that it governs your actions even in trying circumstances?
6. Application: Think of a specific area where your steps “slide” because God’s law is not deeply in your heart. What would it look like to invite God to write His instruction deeper within?
7. Application: How does this verse give you hope when you feel threatened by injustice or by your own failures?