The Sixth Commandment: Thou Shalt Not Kill¶

A Plain-English Summary of the Biblical Evidence

"Thou shalt not kill" is the shortest of the Ten Commandments -- just two words in the original Hebrew. But its reach extends from the first murder in Genesis 4 to the final judgment in Revelation 22, and Jesus expanded its scope from the physical act to the anger and contempt that give birth to it. This study examined the commandment word itself, its pre-Sinai foundation, the detailed legislation in Numbers 35, Jesus's teaching in the Sermon on the Mount, John's declaration that hatred equals murder, Paul's integration of the commandment into the law of love, and its eschatological consequences in Revelation.

The Commandment Word¶

The Hebrew word in the commandment is ratsach, and understanding it is essential to understanding the commandment. Hebrew has four different words that involve killing, each with a distinct range of meaning. Muth is the broadest -- it covers all death and dying. Nakah means striking or smiting. Harag is a general killing word used for war, judicial execution, and personal violence. Ratsach is the most specific of the four: it appears 47 times in the Old Testament, and in every case it describes human-on-human killing.

Importantly, ratsach does not mean only premeditated murder. Numbers 35 uses the same word for both the intentional murderer and the unintentional killer:

"Then ye shall appoint you cities to be cities of refuge for you; that the slayer may flee thither, which killeth any person at unawares." (Numbers 35:11)

"And if he smite him with an instrument of iron, so that he die, he is a murderer: the murderer shall surely be put to death." (Numbers 35:16)

The same Hebrew root (ratsach) appears in both verses -- for the person who kills accidentally and for the deliberate murderer. The Bible distinguishes between the two not by using different words but by examining the internal disposition of the killer:

"If he thrust him of hatred, or hurl at him by laying of wait, that he die... he is a murderer." (Numbers 35:20-21)

"If he thrust him suddenly without enmity, or have cast upon him any thing without laying of wait... and was not his enemy, neither sought his harm" -- this is the unintentional slayer who may flee to a city of refuge. (Numbers 35:22-23)

The determining factor is the heart: hatred, enmity, and malicious intent mark murder. Their absence marks accidental killing. From the very beginning, the commandment is about what is inside a person.

Rooted Before Sinai: The Image of God¶

The prohibition against taking human life did not begin at Sinai. God held Cain accountable for murdering Abel long before any written law:

"The voice of thy brother's blood crieth unto me from the ground." (Genesis 4:10)

And the first murder was preceded by anger. God observed that "Cain was very wroth, and his countenance fell" and warned him that "sin lieth at the door" (Genesis 4:5-7). Anger came first; murder followed. This pattern -- internal hostility leading to external violence -- appears at the very beginning of the biblical record.

After the flood, God gave a universal prohibition to Noah, the ancestor of all humanity:

"Whoso sheddeth man's blood, by man shall his blood be shed: for in the image of God made he man." (Genesis 9:6)

The stated reason is not national law or covenant membership. It is the image of God in every human being. To kill a person is to destroy something that bears the likeness of the Creator. This is a universal principle, given to all humanity, grounded in the nature of what a human being is.

The Mosaic Legislation¶

The case laws following the Decalogue apply the sixth commandment to specific situations. Premeditated murder receives the death penalty with no sanctuary (Exodus 21:12-14). Accidental killing is provided for through six cities of refuge, where the unintentional killer can find protection (Numbers 35:25). No ransom or monetary compensation is permitted for a murderer -- the value of human life cannot be reduced to a price (Numbers 35:31).

The commandment also requires preventive measures. Building a house without a safety railing on the roof brings blood-guilt upon the owner (Deuteronomy 22:8). If an ox known to be dangerous kills someone because the owner failed to restrain it, the owner is held responsible (Exodus 21:29). Even unsolved murders require communal expiation -- the nearest community must formally declare innocence and pray for cleansing (Deuteronomy 21:1-9). The principle behind all of this is that innocent blood defiles the land:

"Blood it defileth the land: and the land cannot be cleansed of the blood that is shed therein, but by the blood of him that shed it." (Numbers 35:33)

Jesus Deepened the Commandment to the Heart¶

In the Sermon on the Mount, Jesus quoted the sixth commandment and then extended its reach far beyond the physical act:

"Ye have heard that it was said by them of old time, Thou shalt not kill; and whosoever shall kill shall be in danger of the judgment: But I say unto you, That whosoever is angry with his brother without a cause shall be in danger of the judgment: and whosoever shall say to his brother, Raca, shall be in danger of the council: but whosoever shall say, Thou fool, shall be in danger of hell fire." (Matthew 5:21-22)

Jesus uses the same judicial language -- "in danger of" the judgment, the council, hell fire -- for anger and contempt that the original commandment used for killing. He is not replacing the commandment; He is filling it full. The progression is striking: anger in the heart, contemptuous speech ("Raca" -- worthless), verbal condemnation ("Thou fool") -- each escalation brings escalating liability.

Jesus then applied this teaching to practical life: if you are at worship and remember that someone has something against you, leave your offering and go be reconciled first (Matthew 5:23-24). The commandment against murder, in Jesus's hands, becomes a commandment for active reconciliation.

Jesus also identified the ultimate source of murder:

"Out of the heart proceed evil thoughts, murders." (Matthew 15:19)

Hatred Is Murder¶

The apostle John carried Jesus's teaching to its sharpest conclusion:

"Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him." (1 John 3:15)

The Greek word John uses for "murderer" here is anthropoktonos -- literally, "man-killer." This same word appears in only one other place in the New Testament: John 8:44, where Jesus calls the devil "a murderer from the beginning." John's theological chain is clear: the devil is the original man-killer; Cain was "of that wicked one" and committed the first human murder (1 John 3:12); and anyone who habitually hates is in the same category as both.

But John does not leave the teaching in the negative. Immediately after identifying hatred as murder, he presents the positive opposite:

"Hereby perceive we the love of God, because he laid down his life for us: and we ought to lay down our lives for the brethren." (1 John 3:16)

The deepest meaning of the sixth commandment, according to John, is not merely "do not kill" but "lay down your life for others." Murder and self-sacrifice are the two poles. The commandment prohibits one and, in its fullest expression, calls for the other.

Paul and the Law of Love¶

Paul quoted the sixth commandment as part of the law that love fulfills:

"Thou shalt not kill... is briefly comprehended in this saying, namely, Thou shalt love thy neighbour as thyself. Love worketh no ill to his neighbour: therefore love is the fulfilling of the law." (Romans 13:9-10)

Paul does not present the commandment as obsolete. He presents it as the content that love enacts. The commandment is the boundary; love is the power that keeps it. Paul also listed murder among the "works of the flesh" that exclude from God's kingdom (Galatians 5:21) and among the vices of those who have abandoned the knowledge of God (Romans 1:29).

James cited the sixth commandment to demonstrate the unity of God's law: the same Lawgiver who said "Do not commit adultery" also said "Do not kill" -- breaking one commandment makes you a transgressor of the whole law (James 2:11). James also traced violence to its root in desire: "Ye lust, and have not: ye kill" (James 4:2), and applied the commandment to economic oppression: "Ye have condemned and killed the just; and he doth not resist you" (James 5:6).

The Final Word¶

The Bible's canonical ending reinforces the commandment. Revelation places murderers among those consigned to the second death:

"Murderers... shall have their part in the lake which burneth with fire and brimstone: which is the second death." (Revelation 21:8)

And in the final chapter, commandment-keepers and murderers are placed on opposite sides:

"Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city. For without are dogs, and sorcerers, and murderers, and idolaters, and whosoever loveth and maketh a lie." (Revelation 22:14-15)

The Bible closes with those who keep the commandments entering the city and those who violate them -- including murderers -- remaining outside.

What the Bible Does NOT Say¶

The text does not say that ratsach means exclusively premeditated murder. Numbers 35 uses it for both intentional and unintentional killing.
The text does not say that the sixth commandment prohibits capital punishment. The same legislation that defines murder prescribes the death penalty as the penalty for it, using a different Hebrew verb.
The text does not use ratsach for warfare. The standard war-killing verbs are different words. Whether the commandment's principle extends to war killing requires reasoning beyond what the text's vocabulary directly says.
The text does not say that the sixth commandment prohibits killing animals. Ratsach is used exclusively for human-on-human killing in all 47 of its occurrences.
The text does not say that every instance of anger is equivalent to murder. Jesus addressed anger directed at a brother -- sustained hostility, not momentary emotion.

Conclusion¶

The sixth commandment prohibits the unlawful taking of human life, and the Bible traces its scope from the external act to the internal root. The prohibition is grounded in the image of God (Genesis 9:6), demonstrated before Sinai (Genesis 4), formalized at Sinai (Exodus 20:13), legislated in detail (Numbers 35), deepened by Jesus to anger and contempt (Matthew 5:21-22), identified by John as hatred of a brother (1 John 3:15), placed within the love framework by Paul (Romans 13:9-10), and carried to the final judgment by Revelation (21:8; 22:15). The commandment addresses every stage of the progression -- from the heart that hates, through the mouth that scorns, to the hand that kills -- and its positive counterpart, revealed by John, is self-sacrificial love.

Based on the full technical study completed 2026-02-27

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