But don't take my word for it. Take the Word's word for it:
137 ("By the rivers of Babylon"):
O daughter of Babylon, that 3 art to be destroyed,
Happy shall he be, that rewardeth thee
As thou hast served us.
Happy shall he be, that taketh and dasheth thy little ones
Against the rock.
139 ("For I am fearfully and wonderfully made"):
Surely thou wilt slay the wicked, O God:
Depart from me therefore, ye bloodthirsty men.
I hate them with perfect hatred:
They are become mine enemies.
140 ("Deliver me, O Jehovah, from the evil man")
Let burning coals fall upon them:
Let them be cast into the fire,
Into deep 2 pits, whence they shall not rise.
141 (which, to be fair, does say, "Let the righteous smite me, it will be a kindness")
Let the wicked fall into their own nets,
Whilst that I withal escape.
143 ("My soul thirsteth after thee, as a weary land")
And in thy lovingkindness cut off mine enemies,
And destroy all them that afflict my soul;
For I am thy servant.
144 ("What is man, that thou takest knowledge of him?")
Cast forth lightning, and scatter them;
Send out thine arrows, and discomfit them.
145 ("I will extol thee, O God")
Jehovah preserveth all them that love him;
But all the wicked will he destroy.
The last one is the prime example -- a beautiful song of praise that makes sure to sprinkle some blood-of-the-wicked as a spice. Not that this is unique to the Psalms; it's just the Judeo-Christian version of jihad, really. Or maybe you could say that the Psalms have a touch of Irish Alzheimer's: Let me forget everything, Lord, except mine enemies.