What does Psalm 37:13 mean?

This is the second half of a contrast presented by David (Psalm 37:12). Those who hate godliness make plans against godly people, whom they also hate. According to this verse, God's response is to laugh, since He knows these evil schemes are doomed to fail.

Psalm 2 describes the wicked peoples' rebellion against God and His anointed. The wicked will try to rid themselves of divine rule, but "he who sits in the heavens laughs; the Lord holds them in derision" (Psalm 2:4). He will break the rebellious nations with a rod of iron and smash them into pieces like a piece of pottery (Psalm 2:9). Revelation 19 describes a future gathering of the wicked to oppose the Lord, but He will strike them down with a sharp sword that proceeds from His mouth, and He will tread the winepress of the fury of the wrath of God the Almighty (Revelation 19:15).

This verse supports the advice given elsewhere in this psalm: that the righteous need not feel downcast or envious because of the wicked (Psalm 37:1–2, 8–9). In the end, the righteous will be rewarded but the wicked will be punished (Revelation 20:11–15).