At this point David turns to the wicked again. Earlier he had spoken of them as "those who tell lies" (v. 6), but this was only one descriptive phrase among many. In these verses (vv. 9, 10) he describes them in terms of their wicked speech or words, probably because he had just prayed for guidance (v. 8) and was thinking of how the words of the wicked can't be trusted. Ah, but it is even worse than that. Their words are destructive, and those who follow them will perish.
One of the complaints unbelievers make against Christians is that their understanding of sin causes them to think of themselves as better than other people. But that is not actually the case. In fact, it is the opposite. The next stanza of the psalm shows what really happens (vv. 7, 8): “But I, by your great mercy, will come into your house; in reverence will I bow down toward your holy temple. Lead me, O Lord, in your righteousness because of my enemies—make straight your way before me.” 

The second stanza (verses 4-6) is a reflection on the wicked, growing out of the psalmist's approach to God in verses 1-3. Each of the preceding psalms has spoken of the wicked, though differently in each psalm. Psalm 1 considered "the way of the wicked" as opposed to "the way of the righteous" (v. 6). Psalm 2 traced the rebellion of the wicked against God, particularly that of the kings and rulers of the earth (v. 2). In Psalm 3 the psalmist has been attacked by the wicked and asks God for protection from them (v. 7). In Psalm 4 the wicked have slandered the psalmist, and he is asking God for vindication. In the psalm we are studying now, David refers to the wicked as those whose prayers the Lord will not hear and in whom he has no pleasure.

The first three verses are an appeal for God to listen to the psalmist's prayer. Many psalms begin in this way, such as Psalm 4, which we just studied last week. Have you ever been stopped in your prayers by doubts about whether you are approaching God rightly? Almost everyone has had doubts like this. If you have, notice what these verses teach us. They teach three things.

I have called this psalm "A Prayer for Coming to God's House" because of verse 7: "But I, by your great mercy will come into your house; in reverence will I bow down toward your holy temple." But we must not think of it as restricted to a formal worship setting. It is actually a generic prayer showing how we must approach God, if we would be heard by him, and what we can expect of him when we do.