Psalm 140 - Matthew Henry's Concise Commentary on the Bible

David encourages himself in God.

The more danger appears, the more earnest we should be in prayer to God. All are safe whom the Lord protects. If he be for us, who can be against us? We should especially watch and pray, that the Lord would hold up our goings in his ways, that our footsteps slip not. God is as able to keep his people from secret fraud as from open force; and the experience we have had of his power and care, in dangers of one kind, may encourage us to depend upon him in other dangers.

(Ps 140:8-13)