Psalm 140

David prays to the God of Psalm 139, who is intimately acquainted with him and 'hems" him in and searches his heart, to now deliver(v1)from evil, and protect (v4) from the wicked, and to preserve from the violent.  

Reminiscent of earlier Psalms, David complains about the wicked all around him.  They have risen up against him on every side, setting plans to snare him, make him stumble, and bring him down.  They slander and scheme.  

But David knows where to turn--acknowledging his God, who has already 'covered' his head in battle.  

Please do not let the wicked's schemes and plans succeed!  He prays for quick and harsh judgement against his enemies, knowing what God has already said about how He will do this.  David longs to be justified, and to see the end of those who hate God.  

He is confident.....knowing that the Lord will maintain His promises, and will deliver the afflicted.  He will not forget His promises.  The poor will receive justice, and the cause of the afflicted will be maintained.  And God will be thanked.  The light at the end of the tunnel is life in His presence forever.