I've recently discovered that an argument I've often seen and sometimes used is based on something untrue. Christians pacifists (and pacifists intending to win over Christians) often make the claim that, since one of the ten commandments says "do not kill", it must always be immoral to kill. I've also seen the sixth commandment come up in lists of supposed Bible contradictions. Most such lists are filled with mainly easily-resolved surface-language differences with the occasional serious difficulty that takes some real work to resolve (although I know of no such difficulties that don't have at least one possible solution, thus showing that it's not actually a contradiction).
One (among several) responses to both of these claims is that the word used for murder in the sixth commandment in fact does not mean killing but simply means murder, so the only kinds of killing that it could be talking about are those that are wrong, leaving it open that there are kinds of killing that are not wrong. It turns out that this isn't true. There are several words for killing in biblical Hebrew, and this term isn't the most common one. It's usually reserved for contexts of killing within the covenant community, usually used in cases where the killing is especially divisive, often with inter-tribal conflicts in mind.
Its most frequent occurrences are all in one chapter, though, and that chapter is Numbers 25, which provides the details of the city of refuge provision of the Mosaic law. The ancient near eastern method of bringing murders to justice was to have an appointed avenger within each extended family or clan unit, who would hunt down and kill anyone who killed one of their own. The city of refuge provision took several of the Levitical cities and made them safe havens from avengers until a trial could take place, thus ensuring justice could be pursued more carefully as long as the accused was willing to flee to one of those cities. If the person was not found guilty of deliberate murder, they could live in the Levitical city until the death of the current high priest atoned for their sin of negligence, but otherwise they could be put to death once convicted.
I don't remember all the details now, but after looking over this with someone who knows Hebrew I discovered that most or all of the occurrences of deliberate murder used the same word as in the sixth commandment, but the term also occurs two or three times of the killing by the avenger, which as far as I can determine is legally sanctioned killing. It's not used of outright death penalties for specific crimes in the Torah, but it is used of the avenger's killing of duly convicted criminals. So what was probably the easiest response to the difficulties I mentioned above doesn't seem to be correct. The pacifist may not be able to claim that what the commandment says not to do can cover every kind of killing, but they can claim that the word can be used for legalized killing. Also, you can't get out of the supposed contradiction simply by saying the word doesn't mean "kill" but means "murder", since the Torah seems to allow instances of killing that use this very word. But I don't think this puts a stop to the kind of view I would defend. It just makes one of the easier and quicker responses no longer as easy and quick as I would have liked.