The sixth of the Ten Commandments is the command of “Lo Tirsach,” the prohibition against murder (Shemot 20:12).
The Sefer Ha’hinuch writes that G-d created the world with the intention that it should be inhabited and developed, and thus taking human life is contrary to G-d’s will for the world. By the same token, the Sefer Ha’hinuch adds, those who destroy the world through their evil conduct specifically should be killed, as their death is actually beneficial for the world’s development.
Needless to say, the prohibition against murder applies at all times and in all places, and it is binding upon both men and women. This prohibition is included among the Seven Noachide Laws, which are binding upon even gentiles. Murder constitutes a capital offense, and thus one who intentionally takes the life of another person in the presence of witnesses, after he had been warned, is liable to execution – specifically, Sayif (killing by the sword). One who accidentally murders must flee to an Ir Miklat (city of refuge), which is a separate Misva and will be discussed in a different context.
G-d warns in the Book of Bereshit (9:5), “Ve’ach Et Dimchem Le’nafshotechem Edrosh” (literally, “But I shall make a reckoning for your blood, for your souls”). The Gemara in Masechet Baba Kama (91) interprets this verse to mean that G-d will hold people accountable for their own blood – meaning, those who take their own lives will be punished in the afterlife. Normally, when a person dies, his death brings atonement for his misdeeds (the Rambam famously writes that some sins can be atoned for only through death), but if one takes his own life, then his death does not achieve atonement. In fact, the Hatam Sofer (Rav Moshe Sofer, Pressburg, 1762-1839) writes that such a person incurs even greater guilt by taking his own life. What’s more, the Tiferet Yisrael (commentary to the Mishna by Rav Yisrael Lifshitz, 1782-1860), in Masechet Sanhedrin (10:12), cites those who say that one who takes his own life forfeits his share in the world to come.
However, while it is clear that suicide is strictly forbidden, the Aharonim debate the question of whether it is forbidden by force of the command of “Lo Tirsah,” or constitutes a separate prohibition. The Sages inferred that suicide is forbidden from the aforementioned verse in Bereshit (“Ve’ach Et Dimchem Le’nafshotechem Edrosh”), but it is unclear whether this verse reveals that suicide is regarded as murder, or if it introduces a separate prohibition of suicide. The Pesikta Rabbati (24) comments that the phrase “Lo Tirsah” implies also “Lo Titrasach” – “Do not allow yourself to be killed.” According to this Midrashic source, it seems, the prohibition of “Lo Tirsah” itself includes not only taking the life of another person, but also taking one’s own life. By contrast, the Minhat Hinuch contends that “Lo Tirsah,” at its core, is a command relating to our interpersonal obligations, our responsibilities towards our fellowman. Necessarily, then, it forbids only taking the life of others, and not taking one’s own life, and the prohibition against suicide constitutes a separate law.
The Minhat Hinuch applies this theory to explain an otherwise perplexing comment of the Rambam. In Hilchot Rose’ah (2:2), the Rambam writes that one who kills himself “sheds blood and is guilty of the sin of murder,” adding that such a person “is liable to death at the hands of G-d, but is not liable to execution by the court.” Later scholars raised the question of why the Rambam found it necessary to state that a person who commits suicide is not liable to execution by Bet Din. Quite obviously, Bet Din cannot put to death somebody who is already dead. The Minhat Hinuch suggests an ingenious explanation, noting the principle of “Kim Leh Be’de’rabba Mineh” – that if one incurs a financial obligation at the time he commits a capital offense, he is exempt from the financial obligation. For example, if a person damages property in the course of murdering somebody, he does not have to compensate for the damage, since he is liable to execution because of that act. The Minhat Hinuch thus suggests that the Rambam’s remark is relevant to the case of a person who damaged property in the course of committing suicide. The Rambam informs us that suicide is a separate prohibition from murder, and thus this individual has not committed a capital offense that would absolve him from the obligation to compensate for the damage caused. As such, the compensation must be paid from his estate.
Others suggest that the Rambam’s remark is relevant to the case of a person who does not kill himself, but makes himself a Terefa – terminally ill. According to many Poskim, damaging somebody’s health to the point where he becomes a Terefa is Halachically regarded as murder. As such, we might have assumed that if one did this to himself, he would be guilty of murder and thus liable to execution. The Rambam therefore clarified that suicide stands separate and apart from murder, such that Bet Din would not execute somebody who made himself a Terefa.
We find in the Talmud and Midrashim a number of stories of lifelong sinners who ultimately repented, and then took their own lives to earn atonement. These stories have led some to maintain that suicide might, at least under certain, extraordinary circumstances, be allowed for the purpose of earning Kappara (atonement). It would seem that this would depend on the question discussed above, as to whether suicide is considered murder. If suicide is included under the prohibition of “Lo Tirsah,” then just as one obviously is not permitted to kill another person even if his intent is for that person to achieve atonement, then one may not kill himself for this purpose, either. If, however, suicide constitutes a separate prohibition, then it is possible, at least in principle, that some exceptions might apply.
A number of Rabbis have noted that a person can be guilty of a form of suicide even without actually killing himself. If a person wastes time, then he is, in a certain sense, shortening his life. He takes a part of his life which could be used productively and instead wastes it on vanity and meaningless activities. He thereby destroys part of his life, and is thus considered as having committed a form of suicide. This prohibition, then, is relevant not only with regard to actual suicide, but also with respect to the need to treat every moment of life as a precious commodity which must be used properly.