What does Exodus 20:13 mean?

The Lord began His declaration of the Law with the Ten Commandments (Exodus 19:5–6; 20:1). These are a framework supporting the rest of the Mosaic covenant (2 Chronicles 5:10). The first four define man's relationship to God (Exodus 20:2–11). The final six outline mankind's relationship to each other (Exodus 20:14–17), beginning with the need to honor parents (Exodus 20:12).

An instruction not to commit murder seems simple, but it is very often misinterpreted. The most common mistake is taking it as an order to never end a life—any life—for any reason. The King James translation uses the English word "kill" because it was mostly associated with illicit violence at the time. In modern speech, the word "kill" has a much broader meaning.

The Hebrew root word used here is ratsach. This implies a predatory, hostile act of taking life, or carelessness that leads to death. This is distinct from terms such as muwth, meaning "slay," or shachat, meaning "slaughter," or harag, meaning "kill." God is not prohibiting all taking of life. Eating meat (Genesis 9:3), offering sacrifice (Exodus 29:38; Leviticus 3:1), capital punishment (Genesis 9:6; Exodus 21:17), self-defense (Exodus 22:2), and warfare (Numbers 10:9) are not defined as "murder" in this context. Acts of negligence or disregard, however, are part of the restriction (Exodus 21:12–29). Accidents were to be judged before being punished (Numbers 35:11–12; Deuteronomy 4:41–43).

Jesus will further clarify this commandment, noting that thoughts can be sinful just as much as physical actions (Matthew 5:21–22).