The traditional rendering, "Thou shalt not kill" (KJV), has fostered broad applications of this commandment in widely divergent areas including abortion, war, and capital punishment. Clearly the death penalty and war cannot be meant, as both of these occur with some frequency in the Old Testament, often sanctioned by God (for example, Deuteronomy 17:7; chapters 20-21). The problem is one of determining the precise meaning of the verb "to kill" (rtsh). Unfortunately, this verb is relatively rare in the Old Testament (46 times, as compared with 201 times for himit and 165 times for harag). Many have tried to limit the translation to "murder," that is premeditated, intentional killing (NEB, NRSV), as opposed to "manslaughter" (unintentional, accidental taking of life). But several of those 46 occurrences refer to unintentional killing (for example, Deuteronomy 4:42; 19:3, 4, 6; Numbers 35:6; Joshua 20:3).
Despite the change in meaning this verb has experienced over the centuries, it seems best to keep in mind the basic biblical insight that life belongs to God, who gives it and who alone has the right to take it away; to accept the somewhat ambiguous nature of this commandment; to render it as "You will not murder"; and not to make sweeping applications with regard to war, abortion, or capital punishment. There are other passages in both testaments that can be marshaled for these issues.
17 You shall not murder.*
New Revised Standard Version Bible: Anglicized Edition, copyright © 1989, 1995 National Council of the Churches of Christ in the United States of America. Used by permission. All rights reserved worldwide. http://nrsvbibles.org