"Phoneuo" in Matthew 19:18 and Romans 13:9

The inconsistency does matter, though not because the two passages mean different things—they mean the same thing, but the translation obscures it.

The Greek word phoneuo carries the meaning “to murder,” yet the KJV renders it as “to kill” in most occurrences except in Matthew 19:18, where it translates the identical word as “do murder.”[1] This creates the false impression that Matthew and Romans are quoting different commandments or emphasizing different concepts.

The real issue is that phoneuo specifically denotes committing murder—the taking of human life for intentional and personal evil reasons—and though there are multiple Greek words translated “kill” in the King James Version, phoneuo and its Hebrew counterpart clearly imply this particular kind of unlawful killing.[2] When the same Greek word appears in both passages, using different English words obscures this precision.

Both Matthew 19:18 and Romans 13:9 are quoting the sixth commandment from Exodus 20:13 and Deuteronomy 5:17, which prohibits murder specifically, not all killing. The commandment doesn’t forbid capital punishment, warfare, or self-defense—it forbids unlawful homicide. By translating phoneuo as “kill” in Romans 13:9 but “murder” in Matthew 19:18, the KJV makes readers wonder if Paul and Matthew are discussing the same commandment, when they plainly are.

Consistency in rendering the same Greek word matters because it helps readers recognize when an author is deliberately reusing terminology to build an argument or when passages are parallel. Here, varying the translation obscures rather than clarifies the theological unity of the two passages.

[1] W. E. Vine, W. E. Vine’s New Testament Word Pictures: Romans to Philemon: A Commentary Drawn from the Original Languages (Nashville, TN: Thomas Nelson, 2022). [See here.]
[2] Thoralf Gilbrant, “Φονεύω,” in The New Testament Greek-English Dictionary (WORDsearch, 1991). [See here.]