Gemara

The Kohanim in Nov had told David that the only bread they have is the Lechem ha'Panim that was removed from the Shulchan. He replied 'I am permitted not only this, to which Me'ilah no longer applies (since it is permitted to Kohanim); it is like Chulin. Rather, I am permitted even the bread put on the Shulchan today (Me'ilah applies to it), for I am dangerously sick.'

Bava Metzi'a 62a (Beraisa - Ben Petura): Two were in a wilderness. One had a flask with enough water to enable one of them to reach civilization. If they share it, both will die. They should share the water, and neither will see the other die;

R. Akiva: "V'Chei Achicha Imach" - your life takes precedence over another's life.

Kesuvos 19a (Rav Chisda): R. Meir says that witnesses are not believed to say that they were forced to sign. He holds that witnesses should forfeit their lives rather than sign falsely.

Objection (Rava): If they would ask us, we would tell them to sign and live. Why shouldn't we believe them?! One may transgress anything to save a life, except for idolatry, incest, or murder.

61a: Rav Ashi saw that Mar Zutra turned pale. Waiters passed, carrying the king's meal. Rav Ashi stuck his finger in the food and put it to Mar Zutra's mouth. Rav Ashi explained to the officers that the food was not fit for the king, for it contains leprous pork. This was verified.

Rav Ashi told Rabanan that he did so because he saw a spirit of leprosy above Mar Zutra.

Yoma 83b: R. Yehudah and R. Yosi were on the road. R. Yehudah was seized by Bulmus (mortal danger due to hunger). Kapchei (he took) a shepherd's bread and ate it. R. Yosi rebuked him for this. When they reached the city, R. Yosi was seized by Bulmus. Everyone gave to him their honey and sweets.

R. Yehudah: I Kapachti a shepherd. You Kapachta the entire city!

Bava Kama 60b (Rav Huna): Plishtim were hiding in stacks of barley of Yisrael. David asked whether he may use others' money (burn the stacks) to save himself. The Sanhedrin answered that a commoner may not, but a king may.

117a: Nochrim forced Reuven to show them money (to take). He showed them Shimon's money. Rav Huna bar Yehudah obligated Reuven to pay.

Rava: Retract the ruling!

(Beraisa): If Nochrim forced Reuven to show them money, and he showed them Shimon's money, he is exempt. If Reuven took the money and gave it to them, he is liable.

(Rabah): If he voluntarily showed them, this is like taking the money and giving it to them.

Nochrim forced Ploni to show them money. He showed them Rav Mari's wine. They asked Ploni to help them carry it; he complied. Rav Ashi exempted him.

Question (Rabanan - Beraisa): If Reuven took the money and gave it to them, he is liable.

Answer (Rav Ashi): That is when Reuven brought the money to them. Here, he helped them only after they already saw it. It is as if they already took it.

Question (R. Avahu - Beraisa): If an extortionist told Reuven 'pass to me a bundle of sheaves or a cluster of grapes', and he passed it to him, he is liable.

Answer (Rav Ashi): The case is, the extortionist was on the other side of a river. He could not have taken it himself.

Support: He said 'pass to me', not 'give to me'.

117b: Reuven had brought his donkey on a ferry. The ferry was in danger of sinking. Shimon threw the donkey overboard, and it drowned. Rabah exempted him.

Objection (Abaye): He saved himself with another's money!

Answer (Rabah): Reuven was a Rodef. (He endangered them through bringing the donkey aboard.)

Rishonim

Rosh (Bava Kama 6:12): Obviously, one may transgress anything for Piku'ach Nefesh other than the three Aveiros! Rather, David asked whether he may burn stacks without intent to pay for them. The answer was that one may not save without intent to pay.

Rashi (60b DH v'Yatzilah): The Sanhedrin ruled that he may not burn the stacks, for one may not save himself with another's money.

Ra'avad (DH Matzil): David asked whether he may burn others' stacks to kill the Plishtim and save Yisrael. The Sanhedrin answered that one may not. In Kidushin (8b), we say that if someone is being chased by a dog, an onlooker must give his food (if necessary) to save the victim. If so, one should be able to take another's money to save himself! We can say that one must save others only when he is present. "V'Hashevoso Lo" includes saving another's body. There is no law to use Ploni's money to save Almoni in Ploni's absence. Even when Ploni is here, he need not save for free. Almoni must pay his losses. Yehoshua enacted that one who is lost in a vineyard may cut vines until he escapes. Surely he must pay for them. If one was pursued and he broke Kelim, he must pay, for one may not save himself with another's money. Even though he is Ones, the Ones Is not due to the owner of the Kelim. Yehoshua needed to enact only because the owner of the vines is not there. This is why they told David that it is forbidden, i.e. without paying.

Or Gadol (1 p.20b DH v'Af): Parshas Derachim asked about how Rashi could say that one may not save himself with another's money. We seet` the Ra'avad holds that letter of the law it is forbidden. It is permitted only due to Yehoshua's enactment. Rashi holds that the Rashba, that the enactment was only for one lost in a vineyard!

Rashi (Yoma 83b DH Kapchei): R. Yehudah took the shepherd's bread by force.

Binyan Tziyon (168): What was R. Yosi's rebuke of R. Yehudah? R. Yehudah did a Mitzvah to save himself! What did R. Yehudah later retort to R. Yosi? R. Yosi did not take by force! Rather, R. Yosi holds like R. Meir, that Piku'ach Nefesh does not override theft, and rebuked R. Yehudah for stealing. R. Yehudah holds like Chachamim, that one may steal for Piku'ach Nefesh. Therefore, R. Yosi's acceptance of food from the entire city is no less Kipu'ach than R. Yehudah seizure from the shepherd. The Halachah follows R. Yosi against R. Yehudah.

Rashi (Avos 5:5): No pregnant woman miscarried from smelling Kodesh meat. Alternatively, if she smelled limbs on the Ma'arachah, we would not let her taste Kodesh meat.

Question (Tosfos Chodoshim): Piku'ach Nefesh overrides everything except for the three Aveiros! If a pregnant woman smelled Kodesh meat, we feed it to her (Yoma 82)!

Answer (Binyan Tziyon): If she asked, we would feed her Kodesh meat permitted to people. The miracle was that even women who did not ask did not miscarry. Only limbs on the Ma'arachah we would not let her eat, for it is of Kodesh and we may not use it to save a commoner.

Rashba (Teshuvah 4:17): Surely, one may steal with intent to repay to save his own life. If one was dying of thirst in the Midbar, and found another's water, should he die rather than drink on condition to repay?! You cannot call him a thief. The owner is obligated to give to him for free, to save his life! R. Akiva exempts one from saving his friend only when it will cause his own death!

Ramban (in Shitah Mekubetzes Kesuvos 19a DH Omar): Some say that Rav Chisda explains letter of the law. A Beraisa (not in Shas) says that R. Meir holds that theft is a fourth Aveirah that Piku'ach Nefesh does not override. Rava rejected this, for we rule like Chachamim. This is wrong.

Ra'avad (in Shitah Mekubetzes 117b DH v'Zeh): Ge'onim said that if Nochrim physically forced Reuven to bring another Yisrael's money, or threatened to kill or torture him in a way that could endanger him, he is exempt. Only the three Aveiros override Piku'ach Nefesh, or even Safek Piku'ach Nefesh. Chachamim taught that one should be killed and not kill, but not that one should be killed and not hand over another's money. However, if they told Reuven 'give to us money. If not, we will torture you', and he brought them Ploni's money, if Reuven is assumed to be wealthy, he is liable, for they wanted Reuven's money. He should have given his own money to save himself. Therefore we can say that the case of Rav Mari was monetary Ones, and not bodily Ones. Had they not seen the money before he carried it for them, he would have been liable. We similarly establish the case of one who gave sheaves to an extortionist. 'Extortionist' connotes monetary Ones. If it were bodily Ones, it would have said 'Listim' (assailant). Some ask from the case of the donkey thrown overboard to save the ferry. To exempt Shimon, Rava needed to say that Reuven was a Rodef. Why wasn't it enough to say that the property needed to save them was designated? Rava gave a better answer. He could even kill (Reuven) if necessary to save himself, and all the more so he could destroy Reuven's property. Also, Rava needed to explain why he was allowed to throw off the donkey more than any anything else on the ferry.

Note: R. Chananel explains that R. Yosi rebuked R. Yehudah for taking all the shepherd's food. Perhaps he wanted R. Yehudah to ponder if indeed all his food was needed for Piku'ach Nefesh, or if it would have sufficed to steal a small amount, and then to buy or request more. Or, he criticized R. Yehudah for refusing a gift from the Nasi (Nedarim 49b). Accepting it could have averted the poverty that now caused him to steal from a shepherd.

Poskim

Shulchan Aruch (CM 359:4): Even if one is in mortal danger and must steal to save himself, he may take only with intent to pay.

Chasam Sofer (OC 208 DH u'Mah she'Chosav): We learn from R. Yehudah that one may steal to save his own life.

Binyan Tziyon (1:167): David said 'you could even give me the new bread, to which Me'ilah applies, for I am dangerously sick.' If one may not steal from a commoner for Piku'ach Nefesh, all the more so from Hekdesh. David answered (like he believed at the time) that one may steal for Piku'ach Nefesh, and even from Hekdesh. Later he asked, and was told that one may not steal even from a commoner.

Afikei Yam (2:32 DH uv'Emes): Since others are commanded to use their money to save Ploni, why can't Ploni use others' money to save himself? Rashi forbids when the others are not there, for then they are not obligated. It seems that Tosfos and the Rosh obligate one who saved himself with another's money only because one need not save from his own money. If others were not commanded to save, Ploni would not be allowed to steal their money, even with intent to pay back. Even Tosfos and the Rosh would not permit saving oneself with Hekdesh, for Hekdesh is not commanded to save him! Also, one cannot pay back Hekdesh like he repays a commoner. We must say that it was permitted because we are not concerned for monetary ownership of Hekdesh, rather, only for the Isur (Shev Shematsa 6:4). The Chidush that the new Lechem ha'Panim was permitted is that we do not say that one may not take from Hekdesh to save oneself.