Thou hast beset me behind and before, and laid thine hand upon me, Psalms 139:5.
The vocabulary of our King James Bible is a marvel of simplicity and accuracy. For anyone who will take the time to learn the vocabulary and grammar of the King James Bible, its words, its diction, its phrases, and the symmetry of its cadences are a treasure. "Beset" is one of those simple words that are used less often in Late Modern English, but gives no difficulty when encountered in the King James Bible.
There a a couple of passages where the meaning is unmistakable in its context. And the men of Gibeah rose against me, and beset the house round about upon me by night, Judges 20:5. A person would have to have at least a master's degree or PhD from a bible college to be able to miss the obvious meaning of "beset" in this context. (Keep in mind that most of the people who say that the King James Bible is too hard to read, are actually well educated folks. They were taught that it is too hard. Just read any of the literature produced by silly Mark Ward to understand that statement.)
Beset the house round about, that gives a clear picture of the word "beset". One of the meanings of beset is "to encompass or surround". We will see in the context in which beset is found in its few other places that it has a slightly deeper meaning. The OED (Oxford English Dictionary) has a number of definitions which include the concept of encompassing something, but given that the idea of being surrounded is also mentioned in the verse we just looked at, we are drawn to see beset as something a little deeper that merely "to surround".
In the 1989 version of the OED, this defintion is given which appears to perfectly pigeonhole what is being said in our King James Bible.
Beset: To circumvent, entrap, catch.
1616 Hee shall make readie his Nets to catch Birds, and to beset the Hares.
In Judges 20:5, we already know that the men of Gibeah are all around the speaker. We see by the word "beset" that it is a mob seeking to capture him. We see that it is done to circumvent the man's freedom of movement. It is to catch him. How easily is this word "beset" used to demonstrate the hand of God upon his saints as when David uses the word in our opening verse Psalm 139:5. David is comforted by being beset by God. He is hemmed in and he likes it.
We should soberly look at Hebrews 12:1, when it warns us of besetting sin; Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us. In this verse we see the contrast between being compassed by something and being beset by something. We are compassed by a great cloud, but the intent is not to take us captive. It is sin that seeks to take us captive as it besets us.