63 Heb “judgment.” This is a metonymy, a figure of speech in which the effect (judgment) is employed as an instrument (sword, spear, or the like), the means, by which it is brought about.
64 The Hebrew term שָׂנֵא (sane’, “hate”) in this covenant context speaks of those who reject Yahweh’s covenant overtures, that is, who disobey its stipulations (see note on the word “rejecting” in Deut 5:9; also see Deut 7:10; 2 Chr 19:2; Ps 81:15; 139:20–21).
65 Or “head” (the same Hebrew word can mean “head” in the sense of “leader, chieftain” or “head” in the sense of body part).

In other versions

ESVEnglish Standard Version

if I sharpen my flashing sword

and my hand takes hold on judgment,

I will take vengeance on my adversaries

and will repay those who hate me.

I will make my arrows drunk with blood,

and my sword shall devour flesh—

with the blood of the slain and the captives,

from the long-haired heads of the enemy.’

“Rejoice with him, O heavens;

bow down to him, all gods,

for he avenges the blood of his children

and takes vengeance on his adversaries.

He repays those who hate him

and cleanses his people’s land.”

NIVNew International Version (2011)

when I sharpen my flashing sword

and my hand grasps it in judgment,

I will take vengeance on my adversaries

and repay those who hate me.

I will make my arrows drunk with blood,

while my sword devours flesh:

the blood of the slain and the captives,

the heads of the enemy leaders.”

Rejoice, you nations, with his people,

for he will avenge the blood of his servants;

he will take vengeance on his enemies

and make atonement for his land and people.

CSBChristian Standard Bible

when I sharpen my flashing sword,

and my hand takes hold of judgment,

I will take vengeance on my adversaries

and repay those who hate me.

I will make my arrows drunk with blood

while my sword devours flesh—

the blood of the slain and the captives,

the heads of the enemy leaders.”

Rejoice, you nations, concerning his people,

for he will avenge the blood of his servants.

He will take vengeance on his adversaries;

he will purify his land and his people.

NLTNew Living Translation

when I sharpen my flashing sword

and begin to carry out justice,

I will take revenge on my enemies

and repay those who reject me.

I will make my arrows drunk with blood,

and my sword will devour flesh—

the blood of the slaughtered and the captives,

and the heads of the enemy leaders.” ’

“Rejoice with him, you heavens,

and let all of God’s angels worship him.

Rejoice with his people, you Gentiles,

and let all the angels be strengthened in him.

For he will avenge the blood of his children;

he will take revenge against his enemies.

He will repay those who hate him

and cleanse his people’s land.”

LEBThe Lexham English Bible

When I sharpen my flashing sword,

and my hand takes hold of it in judgment,

I will take reprisals against my foes,

and my haters I will repay.

I will make my arrows drunk with blood,

and my sword shall devour flesh with the blood of the slain,

and captives from the heads of the leaders of the enemy.’

Call for songs of joy, O nations, concerning his people,

for the blood of his servants he will avenge,

and he will take reprisals against his foes,

and he will make atonement for his land, his people.”

KJV 1900King James Version

If I whet my glittering sword,

And mine hand take hold on judgment;

I will render vengeance to mine enemies,

And will reward them that hate me.

I will make mine arrows drunk with blood,

And my sword shall devour flesh;

And that with the blood of the slain and of the captives,

From the beginning of revenges upon the enemy.

Rejoice, O ye nations, with his people:

For he will avenge the blood of his servants,

And will render vengeance to his adversaries,

And will be merciful unto his land, and to his people.

Public Domain