Gemara

(Beraisa): We assume that Tum'os were previously in the same state and place they were found in.

Kesuvos 75b (Rava): In the Reisha, Mumim were found (on the Kalah) in her father's house, so we assume that they were there from the beginning. In the Seifa the Mumim were found in her husband's Reshus, so we assume they came when she was already married to him.

Rishonim

Rambam (Hilchos Mechirah 22:8): If one gave to Ploni a gift of land, and 100 Dinarim along with it, if the money was in his Reshus at the time, Ploni acquires also the money. If not, he need not give until Ploni can prove that he had Dinarim at the time.

Chasam Sofer (4a DH uv'Makom): We assume that Tum'os were previously in the same state and place they were found in. This is because 'Kan Nimtze'u Kan Hayu they were found here, so we assume that they were here (from the beginning). This is like we say about a Mum found in a Kalah. If it was found in her father's house, we assume that it was here from before Eirusin. If it was found in her husband's house, we assume that it arose there, and not in her father's house. These are the two Chazakos mentioned here. The time they were found is like a Mum found in her father's house, and the place they were found is like a Mum was found in her husband's house. Rashi explained that we derive that all Tum'os are like when they were found, and we are thinking that the same applies to where they were found. This is because there is one source to both Chazakos.

Poskim

Shulchan Aruch (CM 60:6): If Shimon wrote in a document 'I gave to Reuven 100 gold coins to collect from my property', if people do not use such coins for buying and selling, they are acquired through Chalipin, as long as they were in Shimon's Reshus at the time of the Kinyan. If this is not known, Reuven must bring a proof.

Beis Yosef (DH Reuven): Ba'al ha'Itur brings like this from Teshuvas ha'Rif; Ba'al ha'Itur brought proofs against it. Also Sefer ha'Terumos brought this from the Rif, and the Ra'avad's comments. The Ra'avad concluded 'I am not worthy to refute the Rif, but the judge himself can decide to be concerned (for my opinion). Since the Rif and Rambam agree, we rule like them.

Rema: Shimon is believed to say 'I gave them to you', Migo (since) he could have said that they were not in his Reshus.

Beis Yosef (DH Kasuv): Sefer ha'Terumah brings from Teshuvas ha'Rif that we do not follow estimation, for some rich people do not have gold coins. The Rashba (2:194) said that the Teshuvah is not so clear. It seems that Ba'al ha'Itur did not agree.

Beis Yosef (DH u'Mah she'Chasav Rabeinu va'Adoni): The Rosh (v9 5:1) says that one can obligate himself something that he was not obligated. The Tur says that the Rif disagrees. I say that the Rif agrees. The Rif said only that if one admitted that he gave, and it was not in his possession, it is not a gift. The Rosh (Teshuvah 36:8) agrees.

Rema: This is the Rif's opinion. Many disagree, and hold that if one says 'I gave', a litigant's admission is like 100 witnesses. We are not particular about how he gave. Surely he gave in a way that works.

SMA (20): The Rema ruled similarly in 112:3. There, the Mechaber brought two opinions. In Siman 250, he brought only the opinion he omitted here! The Rema there only wrote 'see 60:6.' I answer that here the defendant claims Vadai that he did not have the money at the time. Therefore, ha'Motzi mi'Chavero Alav ha'Re'ayah. In 250:26, the heirs claim 'perhaps he acquired the property afterwards.' Therefore we favor the recipient's Vadai claim. Also Siman 112 discusses heirs. Stam, heirs are not Vadai. There is different, for it discusses land. We cannot say 'it was found here, presumably it was here.' It was always there, just it is a question if it changed ownership.

Shach (28): I say that is 250 is different because the Metaltelim are intact. Therefore, we say Kan Nimtze'u Kan Hayu. Here, the coins are not intact. However, why is Siman 112 unlike Siman 250? There is no source to distinguish land from Metaltelim. Rather, Siman 250 is from the Rashba citing Ge'onim. We do not hold like those Ge'onim, so we do not hold like the Mechaber ruled in Siman 250. The Bach says so. Since the rulings contradicts each other, ha'Motzi mi'Chavero Alav ha'Re'ayah.

Gra (Likut): Also the Taz says that the rulings contradict each other.

Nesivos ha'Mishpat (Bi'urim 14): The SMA is difficult. In EH 108, the Rema says that she must bring a proof, even though she claims against heirs who are unsure! 'It is not known' connotes that the orphans are unsure. We do not make a Vadai claim for the orphans, like the Rosh (Kesuvos 2:7) says. Also the Shach's answer is difficult. If here the recipient must bring a proof because the money is not intact, it should suffice to bring a proof that money was once found with the giver after the gift! This would prove that he had it at the time of the gift, since Kan Nimtze'u Kan Hayu, like it says in Kesuvos. It suffices to bring a proof that she had the Mumim after Eirusin (in her father's house), for Kan Nimtze'u Kan Hayu (so we assume that they were there before Eirusin).

Nesivos ha'Mishpat: I say that there is no question. In Siman 250, the heirs claim that he did not own the Metaltelim at the time of the gift, and we ignore their claim. This is no worse than if he gave the Metaltelim to the recipient, and the recipient deposited them back with the giver. A depositor cannot collect until he brings witnesses who recognized that they are his Metaltelim. If he cannot, the Shomer can say 'yours were lost through Ones. These are others.' If the Shomer died, we claim this for his heirs. We say so in 108:4 regarding property of a business venture. Really, this is not difficult. Kan Nimtze'u Kan Hayu does not apply to a deposit. Just the contrary, it supports the Shomer's claim that the Kelim here are his, and those of the depositor were lost! If one gave all his Metaltelim, he must say that he did not have these at the time, but Kan Nimtze'u Kan Hayu opposes this. Therefore, if one gave some of his Metaltelim, e.g. 100 measures of grain, and now we find 100 measures, we say that they were always here due to Kan Nimtze'u Kan Hayu, but he had another 100 measures at the time of the gift and they were lost, so he is exempt. This is like one who sold 'one of my oxen.' If one of them died, he can say that it is the one he sold (214:2). Here we discuss one who gave 100 gold coins. The giver is believed to say that they were not in his Reshus, for even if they were in his Reshus at the time, he could say that there were another 100 and they were lost. Even if he obligated himself to be liable for Ones, he is exempt, for we do not say Kan Nimtze'u Kan Hayu against a Chiyuv.

Maharit (1:39): A case occurred in which a Kesuvah stipulated that after one of them dies, the other inherits the property, but cannot bequeath it. Rather, after the second dies it must go to the poor. Can the heirs say 'perhaps the property here now was not around at the time of the stipulation'? We claim for orphans whatever their father could have claimed. Even if the poor are Muchzak, the heirs are no worse than a woman to whom was found property in her husband's lifetime. She is believed to say that it is from a inheritance or a gift, even though she had no Chazakah to have property. However, if there was once a Chazakah that all the property he deals with belonged to the poor, and he merely deals with it and 'owns' only what he eats from it, it is all Muchzak to the poor. He is unlike a woman. Even though there was no Chazakah that she has property, there was no Chazakah that what she has is of her husband. Here, all the giver's property is Huchzak to belong to the recipient.

Nesivos ha'Mishpat: In Siman 250 we discuss Metaltelim. In Siman 248:10 we say that this is Kelim he uses, but not merchandise. Therefore we can say Kan Nimtze'u Kan Hayu. Surely Kan Nimtze'u Kan Hayu does not apply to merchandise of wheat and barley, rather, only when we can say that it always belonged to his ancestors (112:2). Siman 112:3 discusses giving his property, i.e. merchandise. The one who holds that the recipient is Muchzak does not say so due to Kan Nimtze'u Kan Hayu, rather, like the Maharit says. There was once a Chazakah that all the property he deals with belonged to the recipient. He merely deals with it and he 'owns' only what he eats from it. He is unlike a woman, who does not buy and sell. Therefore, we do not attribute property found with her to her husband. Here, all the giver's property is Huchzak to belong to the recipient.

Shulchan Aruch (112:3): If one gave his property 'from now and after I die', and it is not known what property he had at the time, some say that the recipient must bring a proof that he had this property at the time. Some say that if we do not know that he acquired property afterwards, everything is in the Chazakah of the recipient.

Rema: The first opinion is primary. See below 250:6.

Shulchan Aruch (250:26): If one gave Stam his Metaltelim 'from now and after I die', and after he died the heirs claim 'bring a proof that he had these Metaltelim at the time he gave the gift. Perhaps he bought them, afterwards', their words have no effect. Presumably, just like they are here now, they were here at the time of the gift.

Rema: See above 60:6.

Shulchan Aruch (EH 108:1): If a Shechiv Mera, or a healthy person who did a Kinyan, said 'my wife should receive like one of my sons', she receives this in addition to her Kesuvah. She gets a share of property he had at the time he commanded, but not what he acquired later, for one cannot be Makneh something not in his Reshus.

Rema: If it is a Safek whether the property was in his Reshus at the time, she must bring a proof.