Here the psalmist describes how the evil that people plan to do to others recoils on its authors (see 5.10). A man digs a pit for someone else to fall into, and then he falls in it himself; see 9.15; 35.7-8; 57.6; Ecclesiastes 10.8. Good News Translation has used the more general figure of being caught in a trap that has been set to catch others, since that is more readily understood.
Pit and hole are synonyms.
In cultures where animals are caught by causing them to fall into holes dug in the ground, the Hebrew figure will serve very well. However, it will often be necessary to indicate the sequence, that is, first digging the pit and then the digger falling in it. It is also necessary in some languages to indicate the purpose; for example, “wicked people first dig a hole to catch other people, and later they themselves fall into that hole.”
The idea is repeated for emphasis in different terms in verse 16; literally His mischief (same word in verse 14b) and his violence act like a boomerang and return to hurt him. Good News Translation has avoided head and pate (the latter is today almost obsolete), preferring to use the pronoun “they.” Another possibility is to have “on himself” in line a and “on his head” in line b (see New English Bible, New Jerusalem Bible). It is often unnatural to have an abstract expression such as His mischief as the instrument or means of “punishment.” This idea must often be recast to say “they do evil things, and these very things cause them to suffer” or “because they do evil deeds their own deeds make them suffer.”
Some languages can keep the form of the Hebrew metaphor mischief returns upon his own head. The following parallel line, however, is even more difficult. On his own pate his violence descends must often be recast if it is to make sense. Violence must often be expressed as a verb or handled as an attributive to an event; for example, “because they use great strength to injure people, they will be injured in the same way themselves” or “because they are people who force others….”
It is quite clear that the two lines of verse 16 are nearly identical in meaning. However, in Hebrew the word order is different, in that the verb returns occurs as the first word in line a and descends as the last word in line b. Thus line b, which repeats and emphasizes line a, does so by reversing the word order. The translator should seek equivalent poetic devices in the receptor language which will be stylistically pleasing and emphatic in their intention.
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 .