Exodus 20:13 (KJV)
Thou shalt not kill.
Many political statements have been made about this verse. This translation has been used by many to support their pacifist desires. However, it seems that most translations have dropped "kill" in favor of "murder".
Exodus 20:13 (NKJV)
You shall not murder.
Is "kill" a valid translation of this word? Why have translations stopped using the word "kill" in favor of "murder"?
The lexicons referenced in Blundin's answer are trying to define the word ratsach throughout the whole of the OT. The differences between these different dictionaries and lexicons imply that the word doesn't have a single unambiguous translation but that it can mean different things in different contexts.
The OP asked what the word ratsach means in Exodus 20:13. In Deuteronomy 35:6-33 the word means “to kill unintentionally,” however unintentional killing is probably not forbidden in the Ten Commandments. So, from within the context of the Ten Commandments, the word ratsach almost definitely means "murder."
In the Jewish understanding, every negative commandment of the Torah (the Five Books of Moses, i.e. Genesis through Deuteronomy) consists of two parts, a notice of what a violation would encompass, and a second mention to indicate the punishment. If you have additional references to a command, they must be teaching something else. See Introduction to Sifra. Similarly, when we look at the commandments of the Decalogue, we study them as a unit because each of the 10 statements (not all are commands) were given to us directly by G-d, and therefore must be of special importance.
Two of the ten commandments are difficult to understand in this context, unless they mean something somewhat different: these are "do not steal" and "do not kill." If we understand these literally, the first is redundant -- the Torah has elsewhere told us of the offense of stealing and of the punishment for theft (Lev. 19:13; Ex. 21:37-22:3); and the second is vague -- the Torah at times commands us to kill (e.g. Deut. 25:17-19) and exempts those persons who are killed accidentally (Num. 35:22). Yet, for the case of intentional murder, there is a punishment described -- death (Ex. 21:12-14), but no separate verse making it a crime.
We see that, other than these two commandments in question, the other commandments of the Decalogue share one aspect -- they describe capital crimes. Idolatry and blasphemy, extreme cases of dishonor to parents, adultery, false testimony in a capital case, and violating the sabbath day all were capital crimes. Kidnapping and murder are described as capital crimes in Ex. 21, but although the punishment is described, there are no verses warning of the offense. The rabbis, therefore, determined that the Decalogue commandment of "lo tignov" applied to the stealing of a person, and "lo tirtzach" meant "do not murder," and not just "do not kill" (See Rashi to Ex. 20:13, citing Babyl. Talmud Sanhedrin 86a).
Given what the various dictionaries define I think "murder" is the more appropriate word, although there is some debate. So you can see for yourself I have posted some citations below.
From the Dictionary of Biblical Languages with Semantic Domains:
8357 רָצַח (rā∙ṣǎḥ): v.; ≡ Str 7523; TWOT 2208—LN 20.61–20.88 (qal) murder, kill, i.e., take the life one another so as to cause a state of death (Ex 20:13; Nu 35:6, 11, 12, 16,17,18,19, 21,25, 26, 27,28, 30,31; Dt 4:42; 5:17; 19:3, 4, 6; 22:26; Jos 20:3, 5, 6; 21:13, 21, 27, 32, 38; 1Ki 21:19; Job 24:14; Jer 7:9; Hos 4:2+), note: this action can refer to an accident, manslaughter, premeditation, or governmental execution; (nif) murdered, be killed (Jdg 20:4; Pr 22:13+); (piel) murder, kill (Ps 62:4[EB 3]; 94:6; Hos 6:9+), note: for piel ptcp. as a noun in 2Ki 6:32; Isa 1:21, see 5344.5
From Strong's Enhanced Lexicon:
7523 רָצַח [ratsach /raw·tsakh/] v. A primitive root; TWOT 2208; GK 8357; 47 occurrences; AV translates as “slayer” 16 times, “murderer” 14 times, “kill” five times, “murder” three times, “slain” three times, “manslayer” twice, “killing” once, “slayer + 310” once, “slayeth” once, and “death” once. 1 to murder, slay, kill. 1A (Qal) to murder, slay. 1A1 premeditated. 1A2 accidental. 1A3 as avenger. 1A4 slayer (intentional) (participle). 1B (Niphal) to be slain. 1C (Piel). 1C1 to murder, assassinate. 1C2 murderer, assassin (participle)(subst). 1D (Pual) to be killed.
From The Abridged Brown-Driver-Briggs Hebrew-English Lexicon of the Old Testament:
vb. murder, slay — Qal murder, slay, with premeditation; c. acc. pers., unawares; slay as avenger; esp. pt. as subst. = slayer, manslayer, without intent; murderer, with intent. Niph. be slain; murdered. Pi. (intens.) murder, assassinate; Pt. as subst. murderer, assassin. Pu.
Swanson, J. (1997). Dictionary of Biblical Languages with Semantic Domains : Hebrew (Old Testament) (electronic ed.). Oak Harbor: Logos Research Systems, Inc.
Whitaker, R., Brown, F., Driver, S. (. R., & Briggs, C. A. (. A. (1997). The Abridged Brown-Driver-Briggs Hebrew-English Lexicon of the Old Testament : From A Hebrew and English Lexicon of the Old Testament by Francis Brown, S.R. Driver and Charles Briggs, based on the lexicon of Wilhelm Gesenius. Oak Harbor WA: Logos Research Systems, Inc.
Strong, J. (1996). The exhaustive concordance of the Bible : Showing every word of the text of the common English version of the canonical books, and every occurrence of each word in regular order. (electronic ed.). Ontario: Woodside Bible Fellowship.
Everyone looks at "kill" vs "murder" but misses the critical "thou" at the beginning of the verse. It is not your right as an individual to decide to cause death. We must take care that we do not cause death accidentally or intentionally. Capital punishment or war are decided by the "men at the gate of the city" or government or by G-d. So, I believe the term should be translated with the broadest possible meaning, which is "kill".
