What does Psalm 41:1 mean?

The Hebrew term dāl refers to weakness, poverty, shortcoming, or helplessness. David is not merely speaking of those who are financially "poor," but also of those disadvantaged or made weak. God honors those charitable and generous to people in need (Proverbs 14:21). Part of that honor is protection and good health, or so David says here (Psalm 41:2).

Of course, David and other biblical writers saw instances where godly, generous people experienced intense troubles (Psalm 73:2–3; Habakkuk 1:2–4). David is not saying that those who help the poor are immune to disease or persecution. Rather, he notes that those who honor God with their lives invite far fewer risks than those who are evil. The person with a righteous, caring reputation is much more likely to be helped by others when he is in trouble. As is noted often in the book of Proverbs, adhering to God's goodness gives a person a much greater chance of success, though not an ironclad guarantee (Proverbs 8:32–36; 12:28).

Perhaps David was reflecting on the teaching in Deuteronomy 26:12–13 about giving to the Levite, the sojourner, the fatherless, and the widow. He had shown kindness to Mephibosheth, who was Saul's grandson and Jonathan's son. He asked his servant Ziba if there were any of King Saul's descendant left. He explained that he wanted to show kindness to whoever remained of Saul's family (2 Samuel 9:3). Ziba named Mephibosheth, who was lame and living in a desert place. David fetched Mephibosheth and treated him royally, even allowing him to eat at David's table (2 Samuel 9:5–13).

Later in this psalm, David seems to connect these comments on care for the disadvantaged with his survival of Absalom's attempted coup (Psalm 41:12).