Gemara

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, and he showed them Shimon's money. Rav Huna bar Yehudah obligated Reuven to pay. Rava told him to retract the ruling.

(Beraisa): If Nochrim forced Reuven, 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 Anas 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 Anas 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 deposited a silver cup by Shimon. Robbers came; he gave it to them. Rabah exempted him.

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

(Rav Ashi): If Shimon is wealthy, presumably, the robbers came for his money (and he is liable for saving himself with Reuven's money). If Shimon is not wealthy, presumably, the robbers came for Reuven's cup, so Shimon is exempt.

Kesuvos 18b: A witness is believed to say 'I signed falsely to save my life', but not 'I signed to save my money', for one cannot establish himself to be a Rasha.

19a (Rav Chisda): R. Meir holds that a witness should forfeit his life rather than sign falsely.

Objection (Rava): If he would ask us, we would tell them to sign and live! One may transgress anything to save a life, except for idolatry, incest, or murder.

33b (Rav): Chananyah, Misha'el and Azaryah (jumped into the furnace, but) had they been lashed, they would have bowed to Nebuchadnetzar's image!

Rishonim

Rif (43a): Showing due to Ones is exempt, for it is Gerama. Bringing is an overt action. A Beraisa teaches that if an Anas told Reuven to pass a bundle, and he did, he is liable, i.e. when the Anas could not have taken it himself.

Nimukei Yosef: If one was coerced Stam, and showed another's money, he is liable. Reasoning obligates one who saved himself with another's money.

Rambam (Hilchos Chovel u'Mazik 8:2): If a Nochri or a Yisrael Anas coerced Levi to show others' money, Levi is exempt. If he gave it to them, he is liable, even if he was coerced, for one who saves himself with another's money must pay.

Rambam (3): If the king forced the Moser until he showed to him storehouses of wine or straw, he is exempt, for if he does not show, they will beat or kill him.

Teshuvas ha'Rashba (1:980): If one was Moser due to financial coercion, he is liable, for he saved himself with another's money. This is like the Beraisa of handing over a bundle. If one was bodily coerced he is exempt, like the thieves who came for the silver cup.

Rosh (6:12): David did not ask whether he may burn others' property to save Yisre'elim. Obviously, Piku'ach Nefesh overrides anything other than the three Aveiros! Rather, he asked whether he may burn them without intent to pay for them. The answer was that one may not save without intent to pay.

Rosh (10:27): If one was not coerced and he showed others' money to Nochrim, he is liable. If he was coerced, he is exempt.

Question: Kesuvos 19a connotes that if witnesses were mortally threatened to sign Sheker, they should do so, and they are exempt!

Answer (Mar'eh ha'Panim): Ones exempts only Gerama, e.g. showing. Signing is an action. The Ra'avad says that there was no Ones when the Anas demanded a bundle on the other side of the river! He is called an Anas, for he takes money without the owner's consent. One who saves himself with another's money from an existing damage is liable. If he prevents damage from coming to himself, even if it causes damage to another, he is exempt.

Rebuttal (Shach CM 388:24): If it was not Ones, this is the primary answer! Rav Ashi should have said so. Why did he discuss two sides of the river?

Yam Shel Shlomo (10:47): The Anas threatened to kill the Yisrael on the other side of the river with arrows.

Poskim

Shulchan Aruch (CM 388:2): If a Moser showed others' money because a Nochri or a Yisrael Anas coerced him, he is exempt.

Rema: If he was coerced to show his own, and also showed David's, he is liable.

Shach (18): This is even if he claimed that (also) David's property is his own.

Shulchan Aruch (ibid.): If he physically gave it to them, he is liable, even if he was coerced, for one who saves himself with another's money must pay. If the king commanded to bring to him wine or straw, and a Moser got up and said 'Ploni has a storehouse of wine or straw in such and such place', he is liable.

Rema: Even if they beat him without saying why, and he showed, he is liable.

Source (Beis Yosef DH u'Mah she'Chosav Oh she'Yisru): We learn from the thieves who took the silver cup.

Rebuttal (Shach 21): The Tur and Shulchan Aruch obligate. What is the reason? He can say 'they were beating me so I would show them money!' Even if it is a Safek, we cannot obligate him due to a Safek! The Gemara says that if Nochrim forced Reuven (Stam), and he showed them Shimon's money, he is exempt. We cannot learn from the silver cup. There, he gave it to them! It seems that the Tur obligates when it is clear that they are not beating him for (i.e. so he will show them) money.

Rema: Only beating and torture are Ones; monetary Ones is not. One who sees damage coming may save himself, even if the result will be damage to another.

Shach (22): The Beis Yosef says that obviously, monetary Ones is not called Ones. The Rashba (980) explains that the Sugya discusses monetary Ones, and exempts if he only showed! I do not know a proof against this from the Gemara or Poskim. The Ro'oh (Sefer ha'Chinuch Mitzvah 236) agrees, and says that his Rebbi and the Rambam say so. Perhaps he had a different text of the Rambam. In any case, the Ro'oh's Rebbi was the Ramban, so one may say 'I hold like the Ramban, Ro'oh and Rashba' (so I need not pay).

Gra (28): Moser is Gerama. It is only a fine that one must pay. Chachamim did not fine one who was physically coerced. One who signs falsely due to monetary Ones is called a Rasha (Kesuvos 18b).

Mahari Adarbi (84 and 106, cited in Hagahos Tur ha'Shalem 54): We learn from Kesuvos 33b that lashes are harsher than death. Imprisonment without lashes is only monetary Ones.