Gemara

Question: Can one be Miskaper (buy and bring an obligatory Korban) with Shevach (increased value of) Hekdesh?

Answer #1 (Beraisa): If one bought a ram for a Sela and fattened it, and now it is worth two Sela'im, it is valid (for a two Sela'im Asham).

Rejection: The case is, he spent a Sela to fatten it (two Sela'im in all). It is not considered Shevach Hekdesh.

Answer #2 (Beraisa): (If it was worth) one Sela at the time of Hekdesh and two Sela'im at the time of Kaparah, he was Yotzei.

Bava Metzi'a 60b (Rava): Mid'Oraisa, there is no Neshech (loss to the borrower) without Tarbis (gain of the lender) or vice-versa. The Torah wrote them separately to forbid Ribis with a second Lav.

69b (Rava): Reuven may tell Shimon 'take four Zuz and lend money to Ploni.' The Torah forbids only Ribis paid from the borrower to the lender.

Rav Papa's son used to take gifts from wax sellers and tell his father to lend to them.

Rabanan (to Rav Papa): Your son is taking Ribis!

Rav Papa: The Torah forbids only Ribis paid from the borrower to the lender. My son takes wages for speaking on their behalf.

Shevu'os 14a: The Tana asked that just like the goat of the Tzibur does not atone for the Kohanim, since they do not pay for it, also the bull should not atone for Kohanim, for they do not pay for it!

Temurah 10a: "Milvad Asher Tasig Yado" refers to Korbanos that others were Makdish for a Nazir.

The verse teaches that one can be Yotzei with others' Korbanos. One might have thought that a Gezeiras ha'Kasuv requires him to bring his own Korbanos.

Rishonim

Rambam (Hilchos Malveh 5:14): Reuven may give a Zuz to Shimon in order that Shimon will lend 100 Zuz to Ploni.' The Torah forbids only Ribis that the borrower gives to the lender.

Rosh (Bava Metzi'a 5:47): The Heter is only when Reuven on his own pays Shimon to lend to Ploni. Also, he may not take back the money he paid from Ploni. Also, Ploni may not tell Shimon 'I will not give to you (to bribe you to lend to me), but Reuven will give to you, because he loves me.' In these cases, it looks like Reuven is Ploni's Shali'ach, so it is forbidden.

Nimukei Yosef (Bava Metzi'a 41a DH Amar): Acharonim permitted Ploni even to persuade his friend Reuven to give to Shimon, in order that Shimon will lend to Ploni, since Ploni does not promise to pay back Reuven. If he promises, it is forbidden even if Ploni does not pay him afterwards, for Reuven is Ploni's Shali'ach.

Ramban (69b): Some forbid persuading Reuven to give to Shimon, in order that Shimon will lend to Ploni, for then Reuven is Ploni's Shali'ach. This is wrong. If Reuven gives his own money, and Ploni does not pay him, why does it matter whether or not Ploni persuaded him?! How is this considered Shelichus?

Ramban (ibid., cited in Nimukei Yosef ibid.): Some permit saying even 'whoever gives will not lose.' This is wrong. Granted, if Simchah is Mudar Hana'ah from Ploni, Ploni may say so (whoever gives to Simchah will not lose, i.e. I will pay him back), for this is not Shelichus (Kesuvos 70b). When there is a fire on Shabbos, one may say 'whoever extinguishes will not lose' (to encourage Nochrim to extinguish - Shabbos 121a). There is different. Since a person panics about his property, if we would not permit this, he would come to extinguish. (It is better that he encourage Nochrim to do so, for even overt Shelichus of Nochrim is forbidden only mid'Rabanan.) For other Isurim of Shabbos, we do not permit this. Also, the Heter for a Mudar Hana'ah was only if Simchah was Ploni's wife, or if Simchah has nothing to eat. Surely it is forbidden regarding Ribis, but persuasion is permitted. Rav Papa's son accepted money for talking to his father (to persuade him to lend). Only an adult son may accept, but not a minor, like we find regarding castration. (If a Nochri stole a bull from his Yisrael friend, castrated it (to improve it for plowing) and returned it, the Yisrael must sell it. Surely, he may sell it to his adult son; he is like a stranger. Rav Acha forbids selling it to his minor son, and Rav Ashi permits.) 'Adult' and 'minor' do not refer to Bar Mitzvah, rather, one who does not eat from his father, and one who does, respectively.

Tosfos (Kidushin 6b DH d'Arvach): The Torah forbids only Ribis that the borrower gives to the lender, i.e. if the lender does not pay back to one who gave a gift to the lender. If he does, this looks like Ribis, and it is forbidden.

Poskim

Shulchan Aruch (YD 160:13): Reuven may tell Shimon 'take one Zuz and lend 10 Zuz to Ploni', as long as Reuven does not ask Ploni to reimburse him for the Zuz he gave.

Beis Yosef (DH v'Gam): The Rosh, Tosfos, Semak and Rashba forbid Reuven to take from Ploni what he paid to Shimon.

Taz (7): All the more so, Ploni may not hire Reuven beforehand to persuade Shimon, and Reuven will give to more or less than this amount to Shimon. This is absolute Ribis!

Taz (6): It is permitted only the way the Shulchan Aruch says, but Reuven may not tell Shimon 'I will pay you a Zuz every month until Ploni pays.' This is totally forbidden, even though the Ribis does not go from the borrower to the lender. Since Reuven accepts to pay Ribis, it is as if he borrowed also the principal, for he must pay until the borrower pays the principal. The Beis Yosef wrote like this in the name of Sefer ha'Terumah, like I wrote in 169:16.

Shulchan Aruch (ibid.): Also, Ploni may not tell Shimon 'Reuven will pay for me.'

Gra (25): This is like saying 'take 100 Zuz and be Mekudeshes to Ploni.' (It is as if Ploni gave the money. The same applies here!)

Shulchan Aruch (ibid.): Some say that also, Ploni may not persuade Reuven to pay Shimon in order that he will lend to Ploni.

Beis Yosef (DH v'Davka): The Rosh forbids. The Rashba said that the Ra'avad forbids, but the Ramban disagreed. Also the Ran and Magid Mishneh wrote like the Ramban. It seems that the Rashba agrees. One may rely on those who permit, for it is a mid'Rabanan matter and the reasoning is proper. The Ramban, Nimukei Yosef, Magid Mishneh and Rashba forbid saying 'whoever gives will not lose.' R. Yerucham wrote that some permit and some forbid.

Gra (24): The Isur for Ploni to pay Reuven is because it looks like Shelichus. The stringent opinion forbids all the more so if he persuades him, for then he is truly his Shali'ach!

Pischei Teshuvah (9): The Shach (18) says (like the Beis Yosef) that even if Ploni persuaded Reuven, it is only Ribis mid'Rabanan. Gidulei Terumah (44:2:14) and Maharshdam (232) disagreed, for those who forbid hold that Reuven is Ploni's Shali'ach, and the Torah forbids. Sha'ar ha'Melech (Hilchos Ishus 5:15) says that they overlooked Tosfos (above) and the Rishonim in Kidushin, who say that even if Ploni pays Reuven what he gave, it is only mid'Rabanan. All the more so, if he only persuaded, which the Ramban permits, those who forbid, forbid only mid'Rabanan.

Rejection (Avnei Nezer YD 151): The Isur to pay back the money is only due to scheming. Those who forbid, forbid due to Shelichus, and perhaps this is mid'Oraisa!

Avnei Nezer (ibid., 5): It seems that the Beis Yosef is correct, for there is no Ribis without Neshech mid'Oraisa. Do not say that the Shali'ach's loss is like the Meshale'ach's loss. Shelichus applies to only to actions, like the Ketzos ha'Choshen (182:1) brings from Perush ha'Rosh (Nedarim 72b). His loss happens automatically. It is as if the Meshale'ach caused the Shali'ach to lose his own money, but the Meshale'ach's money was not lost. The Ketzos similarly explains that a Shali'ach to wear Tefilin does not help, for it is as if the Meshale'ach puts Tefilin on the Shali'ach's head, since Shelichus applies only to the action (but not to the object on which he acts - PF).

Avnei Nezer (7): Reuven may separate a Korban for Shimon, even though the one who gets Kaparah must lose money. In Shevu'os we say that this is why Kohanim do not get Kaparah through the goat, for they do not lose through it. It did not simply say that they do not own it. This shows that for any Korban that one must own, he must lose money through it. Tosfos (Kidushin 8b DH Tzedakah) says that Tzedakah is only if the giver loses money. Kerisus 27a supports this. The Gemara tried to prove that one can get Kaparah through Shevach Hekdesh, but rejected this, for he lost money to fatten it. This shows that he must lose money. Just like one must lose two Sela'im for an Asham that must cost two Sela'im, one must lose money for every Korban that must be his. Do not say that since we hold that one can get atonement through Shevach Hekdesh, he need not lose. Any obligation must come from Chulin money. The second Sela did not come from Chulin (rather, automatically)! We must say that it depends on the primary Hekdesh. Shevach Hekdesh is like the primary Hekdesh.

Suggestion: Even though one must lose money for his Korban, someone else can be Makdish for him. This shows that Shelichus helps for a loss (to be considered the Meshale'ach's loss)!

Rejection (Avnei Nezer 13): A Nochri can separate a Korban for a Yisrael (Temurah 2b), even though a Nochri has no Shelichus! Rather, a verse teaches that one may separate a Korban for someone else (Temurah 10a). This implies that Shelichus does not help for a loss (to be considered the Meshale'ach's loss). If it did, we would not need the above verse! Do not say that the verse teaches that a Nochri can separate. The Gemara said that if not for the verse, we would say that one must get Kaparah through his own money! Likewise, if the Shali'ach pays, there is Tarbis without Neshech, so it is only mid'Rabanan.