Originally Posted by Faith_Machine
killing a prisoner if he measures two lines, but keeping him as a slave if he's only one line. Do we have any information as to what that unit of measurement would be equal to in feet or inches?
The answer is in the position of the wretch when measured.
II SAMUEL 8
1 And after this it came to pass, that David smote the Philistines, and subdued them: and David took Methegammah out of the hand of the Philistines.
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.
3 David smote also Hadadezer, the son of Rehob, king of Zobah, as he went to recover his border at the river Euphrates.
A line is about 4 inches. Having dumped your captive on the ground I understand that any upon examination who were less than 4" could be kept as they would not threaten the status quo. A wretch exceeding 8" would be killed. There might be a temple standard line of 8 inches or even longer but generally a line is about 4 inches and they usually occur in pairs so The Bible is consistent here. What happens to soldiers measured at between 4" and 8" (probably most soldiers in my experience) is anyone's guess. But what exactly is being measured?
From your comments regarding stature in the ancient world I'm assuming it's footware based but that is just a guess and I have no wish to intrude opinion in any way but not much else would require being stretched out on the floor to be measured. I hope that is helpful.