What does Proverbs 24:15 mean?

This verse sounds a warning about aggression against the righteous. To do so is a sign of depravity—imitating the life of "a wicked man"—and such things can bring eternal consequences (Proverbs 24:16). Solomon creates the image of an ambush prepared outside the home of a godly person. Enemies look for an opportunity to destroy; the context of this lesson suggests the good man is weakened by illness or distress.

The Devil schemes against the righteous today as he has in the past. He waits for an opportunity to take advantage of our weakness. Like a predator, he hunts for someone vulnerable to his attacks (1 Peter 5:8). He assaulted Jesus in the desert when Jesus was physically weak after forty days of fasting (Matthew 4:1–3). But Jesus withstood the Devil's temptations. The Devil tripped up Peter when Peter's confidence was in himself instead of in the Lord. Jesus said Satan would sift Peter like wheat, and that is what he did, when Peter denied Jesus three times in the presence of a servant girl and others (Luke 22:31, 54–62).