As the Revised Standard Version footnote shows, the subject of the verbs in these verses is not specified; the Hebrew text says simply “If he does not turn, he will sharpen his sword”–and so to the end of verse 13. Weiser, New Jerusalem Bible, Bible en français courant, and New Jerusalem Bible take the subject of verses 12-13 to be the wicked man himself, the enemy; so in these translations, in verse 12 the man gets ready to destroy, and in verse 13 his weapons turn against him and kill him. (New English Bible is not altogether clear, but seems to make God the subject of all the verbs in verses 13-14.) New International Version (with alternative in the footnote) takes God as the subject of all the verbs in verses 12-13, translating the initial verb, “If he does not relent.”
It seems best to do as most modern translations have done and take the first verb to refer to the wicked, “If they do not change their ways” (literally “turn”; see comments on 6.4), and the other verbs to refer to God. In translation it will often be necessary to avoid the use of an indefinite subject such as a man (Good News Translation “they”) and to say instead “wicked people.” Whether the “if” clause precedes or follows the result clause depends on the usage in the receptor language. Repent is frequently expressed in idiomatic terms; for example, “to change the heart,” “to have a new heart,” or “to walk a new path.”
Vivid figures are used of God getting ready to destroy the wicked: he will whet his sword; he has bent and strung his bow, that is, he is taking aim and is preparing to shoot his arrows (see similar language in 11.2). These expressions depicting offensive action imply a further action, that is, using the sharpened sword and the bent bow to fight the wicked enemy. In many languages such indirect and figurative statements are quite natural, but where there is no apparent connection in meaning, one may make the meaning clear by a purpose clause; for example, “God will sharpen his sword to attack evil people, if they do not repent; he will bend and string his bow to shoot the wicked people, if they do not change their evil ways.” Revised Standard Version has taken the Hebrew verb for “prepare” at the end of verse 12 in the sense of “stringing (the bow)”; New Jerusalem Bible has “he … aims it.” The same verb is used in verse 13a, where Good News Translation has “he takes up,” and Revised Standard Version he has prepared.
Deadly weapons refers to weapons which can cause death, and must sometimes be translated “weapons which kill people.”
The last line of verse 13 is literally “making his arrows into burning (darts).” Most understand this to reflect the practice in ancient warfare of wrapping inflammable material around the tip of the arrow, setting it on fire, and then discharging the arrow. Some, however, take the Hebrew verb to mean “sharpen” (instead of “make ablaze”); so New Jerusalem Bible “makes his arrows sharp.” In languages where bows and arrows are unknown, a more generic term such as “weapons” may be used. In those cases where weapons are unknown in the language, a descriptive phrase must be used; for example, “things people use to hurt other people.”
Biblia Dios Habla Hoy reverses the order of the two lines of verse 13 so as to have the line “he aims his flaming arrows” follow immediately after “he bends his bow” in verse 12b.
Quoted with permission from Bratcher, Robert G. and Reyburn, William D. A Handbook on the Book of Psalms. (UBS Helps for Translators). New York: UBS, 1991. For this and other handbooks for translators see here .