You shall not murder

You shall not murder or You shall not kill, KJV Thou shalt not kill (LXX οὐ φονεύσεις, translating Hebrew לֹא תִּרְצָח la ti-rəṣoḥ), is a moral imperative included as one of the Ten Commandments in the Torah, specifically Exodus 20:13 and Deuteronomy 5:17.

The imperative is against unlawful killing resulting in bloodguilt. The Hebrew Bible contains numerous prohibitions against unlawful killing, but also allows for justified killing in the context of warfare, capital punishment and self-defence.

Retzach
The Hebrew verb רצח (r-ṣ-ḥ, also transliterated retzach, ratzákh, ratsakh etc.) has a wider range of meanings, generally describing destructive activity, including meanings "to break, to dash to pieces" as well as "to slay, kill, murder".

According to the Priestly Code of the Book of Numbers, killing anyone with a weapon, or in unarmed combat, is considered retzach. The code even includes accidental killing as a form of retzach.

The Bible never uses the word retzach in conjunction with war. The Covenant Code and Holiness Code both prescribe the death penalty for people that commit retzach.

The act of slaying itself, regardless of questions of bloodguilt, is expressed with the verb n-k-h "to strike, smite, hit, beat, slay, kill". This verb is used of both an Egyptian slaying an Israelite slave and of Moses slaying the Egyptian in retaliation in.

Another verb meaning "to kill, slay, murder, destroy, ruin" is h-r-g, used of Cain slaying Abel in, and also when Cain is driven into exile, complaining that "every one that findeth me shall slay me" in , he uses the same verb.

Bloodguilt in the Hebrew Bible
The concept of bloodguilt pervades the Bible and entails punishment for the shedding of innocent blood.

The commandment against murder can be viewed as a legal issue governing human relationships, noting that the first five commandments relate strongly to man’s duty to God and that the latter five commandments describe duties toward humans. The commandment against murder can also be viewed as based in respect for God himself. Since man is made in God’s image, the shedding of innocent blood is viewed as a direct offense against the Creator.

The ancient understanding of guilt that is incurred from the shedding of innocent blood is seen in the Genesis narrative, in which Cain killed his brother Abel out of anger, and the cursed Cain for shedding his brother’s blood. The Genesis narrative also portrays the prohibition of shedding innocent blood as an important aspect of God’s covenant with Noah.

The Torah portrays murder as a capital crime and describes a number of details in the moral understanding and legal implementation of consequences.

In contrast, if the killing was accidental, the accused person was permitted to flee to a city of refuge where he would be safe from the avenger of blood. Carrying out the death penalty required the testimony of multiple witnesses; putting someone to death on the testimony of a single witness was strictly prohibited.

The Torah had the expectation that capital crimes would be investigated thoroughly, and moral guilt was attached to failure to investigate crimes thoroughly or failure to give testimony when a call was made for witnesses. The understanding of bloodguilt also required a procedure to make atonement for unsolved murder. If a dead body was found lying in a field, the elders and judges were to carefully determine the distance to the closest town, and the elders of the nearest town were to break a heifer’s neck in a prescribed manner and location.

Responsibility for bloodguilt also extended to areas of gross negligence. A man who failed to build a parapet or railing around the roof of his house would incur bloodguilt if someone fell and died. The owner of a bull who was known to have a habit of goring could be put to death if he failed to keep the animal confined and the bull gored a man or woman to death. The Torah also instructs that homicidal animals were also to be stoned to death and the carcass reviled.

Although judicial mechanisms existed, the Priestly Code permits a close relative of the victim (known as an avenger of blood) to hunt down the suspect and kill them, before any trial has even taken place; however, the avenger of blood was not permitted, by this law code, to kill the suspect while they resided in a city of refuge. The right of the avenger of blood to such revenge ceases, according to the code, after the death of the person who was the Jewish High Priest at the time of the crime

Justified killing: due consequence for crime
The Torah and Hebrew Bible made clear distinctions between the shedding of innocent blood and killing as the due consequence of a crime. A number of sins were considered to be worthy of the death penalty including murder, incest, bearing false witness on a capital charge, adultery, idolatry, etc.

For example, the Exodus narrative describes the people as having turned to idolatry with the golden calf while Moses was on the mountain receiving the law from God. When Moses came down, he commanded the Levites to take up the sword against their brothers and companions and neighbors. The Levites obeyed and killed about three thousand men who had sinned in worship of the golden calf. As a result, Moses said that the Levites had received a blessing that day at the cost of son and brother. On a separate occasion, a blasphemer was stoned to death because he blasphemed the name of the with a curse.

The Hebrew Bible has many other examples of sinners being put to death as due consequence for crimes. Achan is put to death by Joshua because he caused defeat of Israel’s army by taking some of the plunder and hiding it in his tent. David ordered that an Amalekite be put to death because he claimed to have killed King Saul. In his charge to his son Solomon, King David ordered him to deal with the bloodguilt of Joab, who had murdered Abner and Amasa. Solomon ordered that Joab be killed:

The biblical refrain for those justly executed as due punishment for crimes is that “their blood will be on their own heads.” This expresses the idea that those guilty of certain actions have brought the shedding of blood upon themselves, and those carrying out due punishment do not bear bloodguilt.

Justified killing: in warfare
The ancient Hebrew texts make a distinction between the moral and legal prohibition of shedding of innocent blood and killing in battle. For example, the Torah prohibits murder, but sanctions killing in legitimate battle. The Bible often praises the exploits of soldiers against enemies in legitimate battle. One of David’s mighty men is credited with killing eight hundred men with the spear, and Abishai is credited with killing three hundred men. Of course, David himself is portrayed as a hero for killing Goliath in battle.

The 613 Mitzvot extend the notion of lawful killing to the nations that inhabited the Promised Land, commanding to exterminate them completely. Deuteronomy 20:10-18 establishes rules on killing civilians in warfare:
 * the population of cities outside of the Promised Land, if they surrender, should be made tributaries and left alive (20:10-11)
 * those cities outside of the Promised Land that resist should be besieged, and once they fall, the male population should be exterminated, but the women and children should be left alive (10:12-15)
 * of those cities that were within the Promised Land, however, the population should be exterminated entirely (10:16-18), specifically "the Hittites, and the Amorites, the Canaanites, and the Perizzites, the Hivites, and the Jebusites" (10:16-18). Deuteronomy 25:19 further commands the extermination of the Amalekites.

Justified killing: intruder in the home
As described in the Torah, the ancient understanding of the prohibition of murder made an exception for legitimate self-defense. A home defender who struck and killed a thief caught in the act of breaking in at night was not guilty of bloodshed. “If a thief is caught breaking in and is struck so that he dies, the defender is not guilty of bloodshed; but if it happens after sunrise, he is guilty of bloodshed.”

Jewish interpretation
Jewish law views the shedding of innocent blood very seriously, and lists murder as one of three sins (along with idolatry and sexual immorality) fall under the category of yehareg ve'al ya'avor, meaning "One should let himself be killed rather than violate it." Jewish law enumerates 613 Mitzvot, or commandments, including prohibition of murder and a number of other commandments related to the preserving of human life and administration of justice in cases of shedding of innocent blood.

Life is considered very precious, even sacred by Jewish teaching. The Talmud cites the prohibition of shedding innocent blood in Genesis 9:6 as the reason why the death penalty should be carried out against non-Jews as well as Jews, and while faithful Jews are required to obey 613 Mitzvot, gentiles are only obliged to obey the seven Noahide laws, which include the prohibition of murder and establishment of a justice system to administer law honestly. Rabbi Dr. Azriel Rosenfeld offers a representative modern summary of Jewish teaching regarding the command not to murder.

In the Talmud, Genesis 9:5 is interpreted as a prohibition against killing oneself, and Genesis 9:6 is “cited in support for the prohibition of abortion.”

New Testament view
The New Testament is in agreement that murder is a grave moral evil, and maintains the Old Testament view of bloodguilt. Jesus himself repeats and expands upon the commandment, “Do not murder.” Jesus also tells a parable in which a king justifiably destroys a group of murderers. The New Testament depicts Jesus as explaining that murder, as well as other sins, come from the heart.

The New Testament acknowledges the just and proper role of civil government in maintaining justice and punishing evildoers, even to the point of “bearing the sword.” One criminal on the cross contrasts his death as due punishment with Jesus’ death as an innocent man. When Jesus appeared before Pilate, both Pilate and the crowd recognize the principles of bloodguilt. There is no indication in the New Testament that it is unjust, immoral, or inappropriate for secular civil governments to execute those guilty of shedding innocent blood.

Like the Old Testament, the New Testament seems to depict the lawful use of force by soldiers in legitimate battles as justified. The profession of soldier is portrayed in a noble light when the Apostle Paul exhorts the Ephesians to “put on the full armor of God.” Cornelius, the Roman centurion, is portrayed as a righteous and God-fearing man. Jesus praises the faith of a Roman centurion on the occasion of healing the centurion’s servant, and states that he has not found such great faith even in Israel. When John the Baptist was preaching repentance and baptizing penitent sinners in the Jordan river, soldiers came to John and asked for specific instructions regarding their repentance. John the Baptist did not demand that the soldiers renounce their profession, instead he exhorted them to be content with their pay.

Jesus, while not explicitly condoning the use of violence in self-defense, implicitly suggests the need to be prepared for it when he tells his disciples to buy a sword if they do not have one, “now if you have a purse, take it, and also a bag; and if you don't have a sword, sell your cloak and buy one.” However, Jesus was also quick to correct his servant for the improper use of the sword in cutting off the ear of the high-priest’s servant.

Modern Catechism
The modern Catechism of the Catholic Church as developed and published in the 1990s under John Paul II, asserts that the prohibition of murder stems from man being created in God’s image and recognizes the principles of bloodguilt as being necessary for all time. Life is portrayed as sacred, and no one can claim the right to destroy an innocent human being. The sin of shedding of innocent blood cries out to heaven for vengeance.

Legitimate defense is depicted as justifiable, even if the defender deals his aggressor a lethal blow. However, a man should not use more force than necessary to repel an attack. The legitimate defense of persons and societies should not be considered as an exception to the prohibition of murdering the innocent: the preservation of innocent life is seen as the intended outcome. Injury or death to the aggressor is not the intended outcome, it is the unfortunate consequence of using necessary force to repel an imminent threat.

The Catholic Catechism teaches that legitimate public authority has the right and duty to punish criminals proportionally to the gravity of the offense to safeguard the public good. Nonlethal means are preferred, if these are sufficient to defend and protect people’s safety. However, recourse to the death penalty is not excluded, provided the guilty party’s identity and responsibility have been fully determined.

Catholic teaching asserts that abortion is a grave moral evil because the act takes an innocent human life. It asserts that human life must be respected and protected absolutely from the moment of conception. From the first moment of his existence, “a human being must be recognized as having the rights of a person - among which is the inviolable right of every innocent being to life.”

Catholic teaching strictly prohibits euthanasia and suicide as violations of the commandment, “You shall not kill.” Recognizing life and health as precious gifts from God, adherents are encouraged to avoid excess of food, tobacco, alcohol, and medications. Endangering others with excesses speed or drunkenness on the roadway incurs grave guilt. The use of drugs, except on strictly therapeutic grounds is a grave offense. Clandestine production and trafficking in drugs constitute “direct co-operation in evil.”

The Catholic Catechism insistently urges everyone to prayer for the avoidance of war. All citizens and governments are obliged to work toward the avoidance of war. However, it recognizes that governments cannot be denied the lawful right to self-defense, once all peace efforts have failed. The use of legitimate defense by a military force is considered grave and therefore subject to rigorous considerations of moral legitimacy. Elements of a “just war” doctrine are explicitly enumerated.

Reformation and Post-Reformation views
Martin Luther summarized the commandment against shedding innocent blood as grounded in the fear and love of God, and as having both positive and negative aspects: negative in that we must neither harm nor hurt our neighbor’s body; positive in that we must help our neighbor and care for him when he is ill.

In a more detailed teaching, Martin Luther explains that God and government are not constrained by the commandment not to kill, but that God has delegated his authority in punishing evildoers to the government. The prohibition of killing is forbidden to the individual in his relation to anyone else, and not to the government.

In “The Institutes of the Christian Religion,” John Calvin viewed the purport of this commandment as the safety of all being entrusted to each person. All violence and injustice, and every kind of harm from which our neighbor’s body suffers is thereby prohibited. Christians are therefore required to faithfully perform that which is within their power to defend the life of their neighbor, be vigilant in warding off harm, and assist in removing danger when it comes. Calvin asserts that the same rule must also be applied in regulating the mind against anger, arguing that since God sees the heart and mind, the commandment against shedding innocent blood also prohibits murder of the heart and requires a sincere desire to preserve our brother’s life. The hand does not commit the murder unless it is conceived by the mind under the influence of wrath and hatred. According to Calvin, where wrath and hatred dwell, there is an inclination to do mischief, quoting the Bible, “whosoever hateth his brother is a murderer”(1 John 3:15) and “whosoever is angry with his brother without a cause shall be in danger of the judgement” (Matthew 5:22).

John Calvin also makes a case that the command against shedding blood is founded both in the creation of man in the image of God and in the need for a man to cherish his own flesh.

Matthew Henry considered the commandment against killing to apply to both one’s own life as well as the life of one’s neighbor and considered it to apply not only to causing of death but also to prohibit any thing unjustly hurtful to or injurious to the health, ease, and life of one’s own body or the body of any other person. He also ties the commandment against bloodshed back to the command to Noah and his sons in Genesis 9, and he sees it as a command applying to the individual against his neighbor, but not against killing in lawful war, for one’s own necessary defense, or against the government instituting due punishments for criminal offenses. He portrays laying in wait for the blood of the innocent as a grave offense against human dignity as one of the fundamental laws of nature.