There aren't many times the ending of Psalm 139 is applicable to specific situations, but I believe it is in this case:
19 If only you, God, would slay the wicked!
Away from me, you who are bloodthirsty!
20 They speak of you with evil intent;
your adversaries misuse your name.
21 Do I not hate those who hate you, Lord,
and abhor those who are in rebellion against you?
22 I have nothing but hatred for them;
I count them my enemies.
23 Search me, God, and know my heart;
test me and know my anxious thoughts.
24 See if there is any offensive way in me,
and lead me in the way everlasting.
The vengeful wrath against enemies in the Psalms must be read in the light of the prophet Ezechiel who said,
Ezekiel 18:23 Do I take any pleasure in the death of the wicked? declares the Sovereign LORD. Rather, am I not pleased when they turn from their ways and live?
Ezekiel 18:32 For I take no pleasure in the death of anyone, declares the Sovereign LORD. Repent and live!
and (remembering that Jesus Christ is THE Divine Revelation) understand everything in the light of Christ who said
Matthew 5:44 You have heard it said, "Love your friends and hate your enemies," but I say to you, Love your enemies, pray for those who persecute you.
Show respect also for the Lord's Apostle Paul, who explained the Lord's intention:
1 Tim 2:4 He wills that all men be saved, and come unto the knowledge of the truth.