Psalm 9 is David's personal testimony. It speaks briefly of the persecution he faces (v. 13), but David is chiefly thankful that evildoers will face judgment because ″the Lord is known by his acts of justice″ (v. 16). The theme of the oppression of the innocent continues in Psalm 10, but here, David (presumably the author of this psalm) applies what he has just said not only to his own situation, but also to all who are needy and oppressed as a result of the sinfulness of the wicked.

That's why it's important to read Psalms 9 and 10 together. Indeed, in the Greek translation of the Hebrew Old Testament (called the Septuagint), Psalms 9 and 10 are considered one psalm. Furthermore, there's no heading (″For the director of music . . .″) before Psalm 10, suggesting that it belongs with Psalm 9.

Psalm 10 describes the character and deeds of the wicked person. It describes his brutal and exploitative treatment of ″the weak″ (v. 2). The oppressed are sometimes caught in his evil schemes, crushed, and even murdered. We saw in Psalm 1, the introduction to the Psalter, that ″the wicked″ stand in opposition to ″the righteous″. Not only do the wicked revile the Lord (10:3), but they also persistently oppress God's people, who are innocent, helpless, and oppressed (vv. 8, 12, 18).

The abusive conduct of the wicked is rooted in his contempt for God and His laws. In particular, he has convinced himself that he has no need to fear the coming judgment. ″He says to himself, ‘God will never notice'″ (v. 11). When we stop believing in the all-seeing eyes of God, we are easily tempted to indulge in all sorts of evil behaviour.

The apostle Paul quotes Psalm 10:7 in Romans 3:14 as part of his evidence that ″all have sinned″ (Romans 3:23). Psalm 10 isn't simply God's description of a handful of ″really bad″ people, but a diagnosis of the character of the human race.

The problem for the believer is that God sometimes seems to sit back and do nothing while the wicked are on the rampage (Psalm 10:1). David, however, ends his bleak but brutally honest portrayal of the wicked by reminding us to pray, calling on God to not forget the helpless (v. 12), and to continue trusting in Him, because ultimately the Lord will hear and defend His people (vv. 17-18).