GEMARA

(Mishnah): If David asked witnesses to testify that Ploni is a Kohen, and they swore falsely that they do not know testimony, they are exempt.

Question: This implies that if David asked them to testify that Shimon owes Ploni money, they would be liable. The Seifa (35a) teaches that they are not liable unless the claimant asked them!

Answer (Shmuel): They would be liable if someone with a Harsha'ah (power of attorney) asked them to testify.

Question: Neharda'ei taught that we do not write a Harsha'ah on Metaltelim!

Answer: That is only if the defendant denied owing. If he did not, we may write it.

Bava Kama 70a - Version #1 (Neharda'ei i.e. Chachamim of Nehardai): One cannot write a Harsha'ah for Metaltelim (movable objects).

(Ameimar): This is due to R. Yochanan's law (since it is not in the owner's Reshus, he cannot authorize another about it).

(R. Yochanan): If something was stolen, and the owner did not despair, the thief cannot make it Hekdesh, for it is not his. Also the owner cannot be Makdish it, for it is not in his Reshus (under his control)!

Version #2 (Neharda'ei): One may not write a Harsha'ah for Metaltelim that were denied.

Inference: This is only because it looks like Sheker. If they were not denied, one may write it!

RISHONIM

Rif (Bava Kama 27a): The Halachah follows R. Yochanan and (Version #2) of Neharda'ei. If a Harsha'ah was written on denied Metaltelim, we do not force the Nitva to go to Din or swear based on it.

Nimukei Yosef (DH d'Michzi): Harsha'ah is partially a Kinyan, and partially Shelichus. Therefore, it works even when one cannot be Makneh due to R. Yochanan's law, and the Shelichus cannot keep the money for himself.

Rosh (Bava Kama 7:4): In one version, Neharda'ei say that one may not write a Harsha'ah for stolen Metaltelim due to R. Yochanan's law. Just like one cannot be Makdish something not in his Reshus, he cannot be Makneh it. Version #2 does not allow writing a Harsha'ah for denied Metaltelim, for it looks like Sheker. If they were not denied, one may write it on a deposit or something stolen, without concern for R. Yochanan's law. Why does the Rif bring only Version #2? The Halachah follows R. Yochanan! R. Chananel says that the custom is to write a Harsha'ah for denied Metaltelim; he did not know why. R. Tam says that the Halachah does not follow R. Yochanan, for the Halachah follows Version #2, for the Stam Gemara in Shevuos (33b) is like it. The Halachah is that we are not concerned for what seems to be false (Kesuvos 85a, Gitin 26b). Therefore, we write a Harsha'ah on stolen or denied Metaltelim. Even though some disagree about concern for Sheker, e.g. all agree that we are concerned that the date on a Get seem correct, here resembles the cases in Kesuvos and Gitin. Alternatively, even if they are similar, there we are concerned lest we disqualify the witnesses if we find that they were not there on the day the Get was written.

Question: If we are not concerned for Sheker, when the Gemara asked from Neharda'ei, we should have answered that the Halachah does not follow them!

Answer (Rosh): Amora'im argue about this (and we want to answer even for Rav Papi, who is concerned for Sheker). Even though we said that the Halachah does not follow Rav Papi, we challenge Rav from his opinion (Kesuvos 21), and do not answer that the Halachah does not follow Rav Papi. Harsha'ah does not depend on Kinyan. We hold like Version #2 of Neharda'ei, that we write a Harsha'ah on something stolen, even though one cannot be Makneh it, for we hold like R. Yochanan. We must say that it was enacted that Shelichus works as if the Shali'ach himself acquires.

Rambam (Hilchos Sheluchim 3:6): If Reuven claims Metaltelim or coins from Ploni and Ploni denies them, Reuven may not write a Harsha'ah for them. It is like Sheker to say 'I authorize you to take what I have in Ploni's hand' if Ploni already said that he has nothing of Reuven.

Rambam (7): If one had a deposit of coins and wanted to be Marsheh them to a Shali'ach to bring them, Kinyan Chalipin does not help, for coins cannot be acquired through Chalipin. Rather, he gives to him any amount of land, and is Makneh the coins Agav the land. Then, the Shali'ach can go to Din with the Shomer and bring them. This is the law according to the Gemara.

POSKIM

Shulchan Aruch (CM 123:1): According to the Gemara, we write a Harsha'ah only for a deposit that the Shomer does not deny.

Beis Yosef (DH u'Mah she'Chosav Aval): The Tur rules like the Ra'avad, that a Harsha'ah is Batel only if the Nitva (defendant) denied it before it was written, for agrees with the Ra'avad's reasoning. The Rashba brings only the Rif's opinion, that even if the Nitva denies after it was written, it is Batel. Even if he admits to part of the claim, since he denies part, the Harsha'ah is Batel.

Ketzos ha'Choshen (1 DH mi'Dina): One version (70a) says that one cannot write a Harsha'ah for Metaltelim, due to R. Yochanan's law. Rashi says that we discuss a Shomer. I.e., the Shomer has a claim against the owner and refuses to return the deposit before Beis Din rules about his claim. Therefore, the owner cannot be Makneh it.

Shulchan Aruch (ibid.): If the deposit was coins, he must be Makneh it to the Shali'ach Agav (along with) land. One may be Marsheh land even if the other party denies it.

Shulchan Aruch (ibid.): We do not write a Harsha'ah for a deposit that the Shomer denies.

SMA (1): Harsha'ah requires a Kinyan, so the property must be intact, i.e. land, a document with a lien on land, or a deposit, which is not given to be spent and was not denied. We do not write for a denied deposit, for it looks like Sheker.

Shach (1): This is the Rambam's opinion, that Harsha'ah needs a proper Kinyan. We hold like the other opinion, that even if something cannot be acquired, Chachamim made a Shali'ach as if he acquired it.

Question (Tosfos 70a DH Lo): Rashi says that since one cannot be Makneh what is not in his Reshus, if it was lost, the owner could claim it again from the Shomer. This is difficult, for he is no worse than a Shali'ach. If the owner said to give it to a Shali'ach and the Shomer did so, he is exempt.

Answer (Bedek ha'Bayis): It is a mere custom that one who gives it to a Shali'ach is exempt. One who gave it to one with a Harsha'ah is exempt according to letter of the law.

Beis Yosef (DH ume'Atah): The Rashba (1024) says that we write a Harsha'ah even on stolen Metaltelim. The Halachah does not follow him.