Charles Ellicott Commentary Psalms 139:20

"For they speak against thee wickedly, And thine enemies take [thy name] in vain." — Psalms 139:20 (ASV)

For they speak. —A better translation is, Who rebel against you. This is actually the reading of the fifth of the Greek translations preserved by Origen, and entails only a change of the vowel pointing.

And your enemies. —The state of the text is unsatisfactory. The subject of the verb must be that of the last clause, and the rendering "enemies" of a word properly meaning cities is very doubtful, in spite of 1 Samuel 28:16 (but Aquila has “rivals,” and Symmachus “adversaries”), where a textual correction is also required.

Of the various proposed emendations, the simplest produces

“And rise up against them in vain.”