הבא להורגך השכם להורגו
That means that if you know that someone wants to kill you, you must precede and kill him before he kills you. Otherwise, "Thou shall not murder" applies.
More info could be found on Hebrew wiki page about this topic.
The Rambam (Hilchot Rotzeach uShmirat Nefesh 5:11) writes
If the [unintentional] killer is slain within the Sabbath limits of the city of
refuge, the one who slayed him should be executed.
see also end of 5:12
Thus, if a person kills unintentionally and takes refuge at the altar,
and the blood redeemer kills him there, he should be executed as if ...
According to http://www.rci.rutgers.edu/~uzwiak/AnatPhys/Cardiovascular_System.html
the heart touches the chest wall between the 5th and 6th ribs. So if this passage means that he literally stabbed him at the 5th rib, it would have been a very efficient and quick kill.
Although one might think to conclude that homosexuality is worse than murder based on the specific punishments court can impose upon them (stoning for homosexuality and decapitation for murder), this simplistic understanding is not borne out upon further investigation. I know I shouldn't just quote on this site, but no one says it better than the Rambam ...
Mishna in Makoth 2:7
וְכֹהֵן גָּדוֹל שֶׁהָרַג , אֵינוֹ יוֹצֵא מִשָּׁם לְעוֹלָם
A Cohen Gadol who kills goes to the Ir Miklat forever.
They would have to appoint another one, to do the Avoda on Yom Kippour, as the first one loses his job as Kohen Gadol, as the Rambam הלכות רוצח ושמירת נפש at (7:14) says about all those sentenced to Ir Miklat, after they ...
Commentaries available here:
Rashi (verse 16) - Pharaoh's stargazers had told him that a boy who would lead the Jews out of Egypt was being born.
Chizkuni (verse 16) - men were generally those involved in warfare, and Pharaoh was worried about the Jews joining in a war against Egypt. Note that in verse 22, he adopts the "Rashi approach", based on the ...
Rashi to Exodus (1:16) quotes a Midrash that the Pharaoh decreed to specifically kill males since his astrologers predicted that a male would save the Jews. This Midrash is pretty old, and is present in Josephus' Antiquities of the Jews (2:9:2).
Hizkuni (1:16) and Hadar Z'kenim (1:22) suggest that Pharaoh was worried that males in particular would do battle ...
He stays in his Ir Miklat, in all cases even to save a life, as the Rambam explains in Hilchot Rotzeach uShmirat Nefesh 7:8
A person who was exiled to a city of refuge should never leave his
city of refuge, not even to perform a mitzvah or to deliver testimony
- neither testimony involving monetary matters, nor testimony involving a capital case. He ...
The Rambam rules (Rotzeiach 7:5 (English)) that one who is in exile in an Ir Miklat and kills unintentionally inside his Ir Miklat, is 'exiled' to a different neighborhood in that city, where presumably he is safe from threats. A Levi who lives in an Ir Miklat ordinarily who kills unintentionally is exiled to a different Ir Miklat.
There is no question that war, self-defense, official executions and certain other cases of para-Halachic killings are either sanctioned, required, or otherwise allowed after the fact (and even rewarded).
The questions as to why are not answered in a generality; there has been much discussion about each case, with separate explanations for each.
As to your ...
I see several questions in your post. I'll try to answer them one by one.
what does, "Thou shall not murder" mean anyway?
It means that human life is holy, and Torah prohibits taking any human life. Pretty similar to how most people generally think about killing.
The Torah seems to allow many instances of killing
Original question author didn't ask about ...
This is the matter of a Tannaic dispute recorded in the Mishna (Makkot 2:7), Makkot (11a):
רוצח שיצא חוץ לתחום, ומצאו גואל הדם--רבי יוסי הגלילי אומר, מצוה ביד גואל הדם, ורשות ביד כל אדם; רבי עקיבה אומר, רשות ביד גואל הדם, וכל אדם אין חייבין עליו.
A murderer who left the bounds [of the city of refuge] R. Jose the Galilean says: it is a mitsvah for ...
The Midrash Raba 1:28 says it was justifiable:
One time, an Egyptian taskmaster went to a Israelite kapo and looked at his wife, who was beautiful without blemish. He got up at cockcrow and removed him from his house and (the Egyptian) returned and bedded his wife, who thought he was her husband…. Once the taskmaster knew that [the husband] knew ...
A Medrash states that G-d offered the Torah to the children of Eisau. They rejected it, saying they could not accept this very commandment against murder. This begs the question: Eisau's descendants also have a law against murder! Why couldn't they accept G-d's law if it was already illegal by their own standard?
Rabbi Yaakov Weinberg ZT"L answers as ...
See Rabbi Michael Broyde's excellent essay (entitled, in various versions, either "Only the Good Die Young" or "Judaism is Not a Suicide Pact!") here.
It is clear to me that the vast majority of
contemporary poseqim agree with R. Shaul
Yisraeli, and for that reason, even as there are
numerous sefarim that deal with religious life in
Ohr Someach clearly states:
Jewish law forbids euthanasia in all forms, and is considered an act
of homicide. The life of a person is not "his" - rather, it belongs to
the One Who granted that life. It may be therefore be reclaimed only
by the true Owner of that life. Despite one's noble intentions, an act
of mercy-killing is flagrant intervention ...
The Sefer HaChinuch writes as follows:
Sefer HaChinuch Mitzvah # 410
ונוהגת מצוה זו בזמן שישראל על אדמתן וסנהדרין של שבעים ואחד יושבין
במקומן המוכן להם בירושלם לדין דיני נפשות
And this commandment is operative during the time that Israel is on their land and the
Sanhedrin of 71 is sitting in their place that is prepared for them in
Rabbi Yonason Eibushutz answered humorously that disposing of two evil doers ( Bigsan and Teresh) is better than one ( Ahashverosh)
The midrash (footnote 73) and Sefarim Chitzonum writes that Bigsan and Teresh were in cohoots with Haman. If Ahasverish was killed Haman would have taken his place. In that case it is clear that Ahasverosh is better than Haman. ...
Rabbi Yosef Karo (1488 - 1575)states in Shulchan Aruch, (The Code of Jewish Law) that if a physician is able to heal a patient and refrains from doing so, this is considered murder. Yoreh Deah, 336:1
Rabbi Moshe Isserles (The Rema 1520 - 1572), writes on the Shulchan Aruch (Code of Jewish Law), that any act involving touching or moving a "gossess" (a term ...
If not for the prohibition, murder would carry no defined penalty in civil courts. The Torah prohibition makes murder always a capital crime. Same with stealing - if there was no explicit mitzvah, there would not be a set punishment entrusted to earthly courts.
Yes. Jews killed many prophets. And here is a proof from 1 Kings 19 (14).
Then the Lord spoke his word to him: “Elijah! Why are you here?”
10 He answered, “Lord God All-Powerful, I have always served you as
well as I could. But the people of Israel have broken their agreement
with you, destroyed your altars, and killed your prophets with swords.
Tosfos (Sanhedrin 74b s.v. והא אסתר) says:
ורוצח גופיה כי מיחייב למסור עצמו ה"מ קודם שיהרג בידים אבל היכא דלא עביד מעשה כגון שמשליכין אותו על התינוק ומתמעך מסתברא שאין חייב למסור עצמו דמצי אמר אדרבה מאי חזית דדמא דחבראי סומקי טפי דילמא דמא דידי סומק טפי כיון דלא עביד מעשה
The case of murder itself, he is obligated to sacrifice himself before he kills ...
First, the concept of killing a non-guilty party in self defense is learned from the Gemara in Sanhedrin 82a. (See also the commentary of the Rosh to this Gemara; 9:4) When Pinchas was (doing the right thing; hence not guilty; see Numbers ch. 24) chasing after Zimri, to kill him with a spear, the Gemara explains that Zimri was allowed to kill Pinchas in self ...
Mishna Sanhedrin 8.6
[A thief] who comes through a tunnel [into one's house] is judged on the basis of his end. If he came through a tunnel and broke a jug: if he has blood-guilt, he is liable; if he does not have blood-guilt, he is exempt.
הבא במחתרת נדון על שם סופו היה בא כו': וכן הבא במחתרת ידוע הוא שכונתו שאם יעמוד בעל הבית להציל ...
Exodus Rabbah 1:26 brings this midrash: one day when Moshe was a child he grabbed Paro's crown and the court magicians counselled Paro to have him killed lest he usurp the throne. Ultimately a test was proposed and Moshe passed (with Gavriel's help), so he was allowed to live. But it's not unreasonable to think that the magicians would continue to caution ...
Judicial execution is not the same as murder. The same torah that says "do not murder" also calls for the death penalty for certain transgressions, so there must be a difference.
Tractate Sanhedrin discusses capital punishment in a fair bit of detail. There are strict rules, but nonetheless a death sentence is possible and does not violate lo tirtzach.
Hirhurim quotes R' J.B. Soleveitchik regarding an earlier event similar to Masada where Josephus' army committed suicide rather than surrender. Josephus, however, survived, surrendered and became a Roman citizen:
I would not say that Josephus lacked the courage to commit suicide. From a halakhic point of view, Josephus may not have been permitted to do so....
The Ramban on the story quotes the Rambam as saying that the inhabitants of Shechem were required to judge (the person) Shechem and did not. As such, they did not fulfill the obligation of the descendants of Noach to judge justly. A descendant of Noach that fails to fulfill one if his 7 obligations (namely 1. belief in the creator, 2. prohibition of incest, ...
Rambam addresses this (Melachim 6:4): "And do not kill women or children".
This is talking about a case where the women and children are not part of the war - as opposed to cases where children and women are part of the war effort, for instance, by being soldiers themselves, or the nations which we are commanded to annihilate.
Sifri (page קפז) says ...