HOW SHOULD WE RESPOND WHEN THE ENEMY SUFFERS?

Psalms 58:10  The righteous shall rejoice when he seeth the vengeance: he shall wash his feet in the blood of the wicked. (KJV) Proverbs 24:17  Rejoice not when thine enemy falleth, and let not thine heart be glad when he stumbleth: (KJV)

Clearly, it depends on whether the suffering is the result of God's vengeance (which we should rejoice at) or merely our enemy falling due to their own mistakes (which we should not rejoice at).  Not a contradiction.