What does Psalm 41:3 mean?

This continues David's statement that God provides healing and protection for those who care for the disadvantaged (Psalm 41:1–2). David knew full well that even righteous people can suffer sickness, death, and defeat (Psalm 12:5; 22:1; 25:17). Yet this general principle applies: those who follow godly wisdom are less likely to suffer consequences than those who choose evil (Proverbs 8:32–36). A strong person who righteously protects the weak reflects that kind of godliness.

This verse serves as a transition, where David mentions the idea of the Lord healing someone from illness. In the following verse, he will speak of God's forgiveness of sin as a form of "healing." David's sin in the case of Bathsheba (2 Samuel 12:7–9) led to drastic consequences. Those included a rebellion by his son, Absalom (2 Samuel 15—18). Other psalms also express David's remorse for his crimes (Psalm 38; 39; 51). He realized that the Lord accepts the prayer of a repentant believer. In the remainder of the psalm, he describes the attacks of his enemies and his confidence that God will bring him through those dangers.

The apostle James speaks of how a believer ailing due to sin can receive healing. He writes: "Is anyone among you sick? Let him call for the elders of the church, and let them pray over him, anointing him with oil in the name of the Lord. And the prayer of faith will save the one who is sick, and the Lord will raise him up. And if he has committed sins, he will be forgiven" (James 5:14–15).