Challenge: Without looking it up or referring to a commentary, can anyone explain what's going on in this verse?
2 Samuel 8:2
2 And he smote Moab, and measured them with a line, casting them down to the ground; even with two lines measured he to put to death, and with one full line to keep alive. And so the Moabites became David's servants, and brought gifts.
i know a "line" in biblical times was a knotted cord used for measuring short distances or very large things.. ... (like a modern measring tape).... ... the knots were placed every 18 inches or every "cubit" according to tradition..... ....but i don;t remember off the top of my head what was happening there in 2nd samuel 8..... yet i do remember 2nd samuel recounts wars and israels campaigns against many different armies... ... ....
and without looking anything else up and seeing what the surrounding verses say... or without seeing if that incident is recorded or referred to somewhere else in the bible... i have no way of knowing whether david was measuring the height of the moabites and killing everyone who was either too tall or too short...... (which conquerers sometimes did...) ........ or whether he had them all line up..... stretched the line along the assembled length of them... and then killed eveyone within the first 2 measured groups and spared the third.............. there is just no way of knowing.......and 2nd samuel doesn;t say how many moabites there were..... but apparently david "smote" a sizeable group of moabites beforehand..... (or defeated them in battle).... and then killed as many as 2 thirds of the moabites that survived the intitial besmittance arbitrarily and by the numbers.... ... and from the looks of it without discrimination or descretion to persons...... .
in many ancient armies of that time... if a particular battalion or group of soldiers lost a battle or performed poorly.... the commanders would make an example of them, by lining up the surviving soldiers and killing every 10th man in line... as both a punishment and as a warning to their other troops.... ...thus the term to "decimate" was derived.....or to cut down a force by 1 tenth...... ..they did this to their own troops...by the numbers and without regard to who they were...
so when rebels or enemy armies were captured ....or if they surrendered... ...the conquering army did the same thing but usually did a lot worse than just to decimate them.... and sometimes would kill them all or leave only a small handful of survivors to become slaves ....or would allow a few of them to go back home and tell the tale of defeat to their other countrymen........ thus warning all others not to make war against that particular army again or commit the same mistakes...... ......
my thought is that david did not want to kill all the moabites... and wanted some to survive and become servants..... but he wanted those survivors to be good and well behaved ... obedient servants..... perhaps he thought if the moabites saw 2 thirds of their fellow brothers in arms measured and then cut down by a cold equation of numbers it would make them think twice about ever fighting against david or israel again............ ... ..it sounds harsh by todays standards.... but leaving 1/3 alive was probably considered merciful by battle commanders of the time who didn;t have modern sensitivities. .......
anyway...... it;s all my opinions... (except for the history part)..... and what i wrote about davids actions is probably completely wrong.... but it is the best i can do with a verse cut out on it;s own.... left flapping in the breeze.... ... and without being able to see it in proper context............. .... 
Pretty good, aleshanee!
They were killing the descendants of the giants. Those who were two lengths of rope, i.e., twice the size or taller than normal men, were killed.
ok.... so then david was killing off the remnants of the anakim or emites.....and anyone who might have been a descendant of a moabite/anakim union?..... ... i wont say i doubt it.... ..... but is there any other part of the bible that supports that or recounts that incident?.... .....i know there were descendants of the anakim still among the moabites at the time of david..... ... but so many that they made up 2 thirds of the fighting force?.......
thinking this might just be a king james version issue.... (which is my favorite version and which i do most of my study in).....i checked multiple other versions of this chapter in samuel.... even the greek ...and hebrew versions translated into english..... then read the latin version for myself but double checked it against an english translation too.... .... and none of them mentioned the anakim or emites by name.... or even the raphaim in 2nd samuel 8.. .... ... .... however..... all of them do agree that david forced the moabites to lie on the ground and then measured them against 2 lines to be put to death and 1 line to be allowed to live....... but none of them are clear that it was the actual height of the moabites being measured....(line laid vertical against each individual)... .. in fact they all leave it open to interpretation that it could have just been an arbitrary counting off the numbers en-mass.... by laying the line horizontal along the whole group then killing the ones who fell within the 2 lines together right where they lay.....
i have to admit that part of 2nd samuel is not something i have devoted in depth research and study to.... ....though i know i have read over it multiple times over the years and in virtually all the versions and translations i was fluent or literate in.... ... ....and though i might have overlooked it, i couldn;t find any reference to this incident in the books of the apocrypha either ...... .... i did not check any bible commentaries.... .. generally i don;t put much stock in them..... ..they are written by men mostly offering their opinions and not proven to have been inspired..... ..... though it;s doubtless a few of the theologians writing commentaries would like us to think they are...... ..
but anyway..... ..thanks for posting this thread..... it has me interested in learning more about what actually happened in that chapter..... so far i only devoted a few hours to it this afternoon.... but i definitely want to read more.... ..
I purposely picked one of many translations that makes the passage difficult to understand. In fact, most translations make it difficult. Here's one that makes it much easier to see that those who were measured with 2 lengths of rope were the ones to be killed, and those measured out at 1 rope length were to be spared:
2 Samuel 8:2 Common English Bible (CEB)
2 David also defeated the Moabites and made them lie on the ground, measuring them with a rope. He measured two rope lengths for those who were to be killed and one rope length for those who were to be spared. The Moabites became David’s subjects and brought him tribute.
i can see how the second quote from the (c-e-b) would be easier for most english only readers to understand..... ...but in truth the first quote you posted also made it clear that the moabites measured with 2 lines were the ones who were killed.... and the ones measured by one full line were the ones allowed to live..... .... and in fairness i don;t see the second quote specifically ruling out the possibility that it was groups of moabites being measured all together at once while on the ground.... nor does it specifically confirm that it was the height of each moabite being measured and not simply the size of the groups........ ... .....to me both versions say the same thing.... ....they just say it in a little different way.........
but it makes sense that david would want to wipe out the lineage of the giants.... ... and i;m not discounting or even doubting that might be what he was doing...... ......but i think it would have been much more clear to understand if the passage was continued with something along the lines of.... .. "and thus david smote the remnants of anakim"... ... or..... "the descendants of raphaim and emim were no more......".... ... other actions of such significance are notated that way in other parts of the bible..... ... .......i checked a few online commentaries on this scripture.... and the questions... doubts... and controversy continues there the same as here..... some say they think david was cutting the moabites down by the numbers... killing 2/3 .and leaving 1/3 alive..... .. and others say they think he was specifically targetting the giants...... ..... ..
but the question that keeps coming up in my mind.... . though i didn;t see it brought up in any of the commentaries... ... is why would david need to measure moabites with lines to single out the ones who were twice as tall as an average man?.... ..... wouldn;t that be easy to see plainly enough while they were all standing up?.... ........ i don;t know..... maybe his decision had something to do with immobilizing them first so they couldn;t resist or fight back?..... .. ..
Normally I'd dismiss the idea they were giants, but even Wikipedia makes a connection:
Anakim (Hebrew: עֲנָקִים ‘Ǎnāqîm ) were described as a race of giants, descended from Anak, according to the Tanakh. They were said to have lived in the southern part of the land of Canaan, near Hebron (Gen. 23:2; Josh. 15:13). According to Genesis 14:5-6 they inhabited the region later known as Edom and Moab
Now, this is not definitive proof that these were giants, especially since Joshua supposedly drove them out of their "home towns". But there could have been a remnant, like those mentioned in Deuteronomy (Rephaim were giants):
Deuteronomy 3:11 (Now only King Og of Bashan was left of the remnant of the Rephaim. In fact his bed, an iron bed, can still be seen in Rabbah of the Ammonites. By the common cubit it is nine cubits long and four cubits wide.)
Bashan is east of the Jordan, north of Moab, which is also east of the Jordan.