Gemara

43b - Question: From when does the lien to collect a Kesuvah begin?

Answer #1 (Rav Huna): She collects 100 or 200 (Ikar Kesuvah) from the time of Kidushin. She collects Tosefes (any addition to this) from the time of Nisu'in.

Answer #2 (Rav Asi): She collects the entire amount from the Nisu'in.

(Rav Huna): If a (divorced or widowed) woman is holding two Kesuvos, one for 200 and one (with a later date) for 300, she may collect 200 from the earlier date or 300 from the later date.

Question: According to Rav Huna's answer above, she should collect 200 from the earlier date and 100 from the later date!

Counter-question: Why doesn't she collect 500, i.e. 200 from the earlier date and 300 from the later date?

Answer: Since he did not write 'I am adding 300 to your 200', he intends that she may collect 200 from the earlier date, or 300 from the later date.

Answer: Likewise, since he did not write that he is adding 100 to the first 200, she pardoned the lien from the earlier date.

(Rav Huna): She may collect whichever Kesuvah she wants.

Suggestion: He argues with Rav Nachman, who says that if Ploni has two documents (for the same property) with different dates, the latter is Mevatel (invalidates) the former.

Rejection: Rav Papa taught that Rav Nachman admits that if the second document adds a date tree, it was written for the addition and does not Mevatel the first. Also in Rav Huna's case, the second Kesuvah adds to the first!

When both are sale documents or both are gifts, the latter is Mevatel the former.

Question: What is the reason?

Answer #1 (Rafram): Ploni requested another document because he agrees that the first one is invalid.

Answer #2 (Rav Acha): Ploni pardoned the earlier lien.

Three laws apply according to Answer #1, but not according to Answer #2:

Ploni invalidates the witnesses on his first document (he cannot use them for other testimony). Ploni must pay for Peros he ate from the land in the interim between the two dates. The seller pays the property taxes for the interim.

The Halachah is, a woman collects the entire amount from the Nisu'in.

89b (Mishnah): If a woman has two Kesuvos and one Get... she collects only one Kesuvah, since a man who remarries his ex-wife does so on this condition.

Question: This implies that she can collect either Kesuvah, unlike Rav Nachman!

Answer: The case is, the second Kesuvah is greater than the first. Rav Nachman agrees in such a case that it was written for the addition.

Rishonim

Rif: If two documents have different dates, the latter is Mevatel the former. If the second adds on a date tree, it was written for the addition. When both are sale documents or both are gifts, the latter is Mevatel the former. Ploni requested another document because he agrees that the first one is invalid, or because he pardoned the earlier lien. These answers argue about invalidating the witnesses on the first document, paying for Peros eaten in the interim, and paying the taxes for the interim. The latter is Mevatel the former only regarding (sale of) land or Kesuvos. If they are admissions and loans, Ploni collects each from its date. We do not say that they are for the same loan, even if they are for the same amount. We learn from Bava Basra 172a. (The Gemara says why we do not agree to convert a loan document for 100 to two documents of 50 each. It is clear that both would be collected.)

Rambam (Hilchos Zechiyah 5:9): If both are sale documents or both are gifts, if the latter adds anything, the first is valid. The latter was written just for the addition. If the latter does not add anything, it is Mevatel the former. The Acharayos is only from the latter date. Therefore, Ploni must return all the Peros he ate between the dates. If there are property taxes on the property, the giver or seller pays them until the second date.

Rosh (4:5): When the latter document adds a date tree, the first is valid and Ploni acquires the tree through the latter. When there are two Kesuvos, for 200 and 300, why doesn't she get 200 from the first date and 100 from the latter date? Also regarding a field, he did not explicitly say 'I add a date tree to the first document!' Rashi does not say that both are valid. Rather, Ploni can use the first document to collect from the first date without the tree, or the latter to collect from the second date including the tree. The Rif says the same in a Teshuvah.

Ran (DH Shnei): If both are gifts, there is no difference regarding collection, so surely the second was Mevatel the first! However, even regarding gifts, the first gift cannot be seized by creditors who lent to the giver in the interim.

Ran (ibid.): This is when Ploni did not yet acquire through the first document, and now he received both documents. If he previously acquired the first document, one who lent afterwards cannot collect from Ploni. The land does not leave Ploni's Reshus through his pardon. In such a case, the latter document is Mevatel the first. However, the Rambam connotes that we care about collection dates only regarding loan documents, but regarding sales, the Ikar is from the first date and the Tosefes is from the latter date.

Rosh (ibid.): 'He wrote it for the addition' connotes that both documents are valid. R. Yitzchak bar Baruch says that the cases are different. One who writes Tosefes normally writes 'I add this amount.' Since he wrote both Kesuvos Stam without mentioning Tosefes, he shows that he did not intend to add. Rather, the latter is Mevatel the first. Sellers do not normally write 'I added this to the first sale.' Stam, we say that he did not Mevatel the first document. The first is valid, and Ploni collects the tree with the latter. This is the primary opinion.

Question: The Halachah follows Rav Nachman in monetary laws. Also, Rafram and Rav Acha argue according to him. The Sugya on 89b is like him. But we ruled that a woman collects the entire Kesuvah from Nisu'in!

Answer #1 (Rosh): I hold that the Gemara discusses when no Kesuvah was written from Eirusin. Therefore, this is unlike two documents.

Answer #2 (Rosh): The custom is to combine the Ikar and Tosefes in the Kesuvah after Nisu'in. Even if a Kesuvah was written from Eirusin, this was so she will receive Ikar Kesuvah if she will be widowed or divorced from Eirusin. There is no such custom for monetary documents; the latter is Mevatel the first.

Rosh (ibid.): If both are sale documents or both are gifts, the latter is Mevatel the former. Rafram says that this is because Ploni admits that the first was Pasul. I.e. the witnesses are Pesulim, or he himself forged their signatures. Therefore, any document Ploni brings with these witnesses is Pasul. Rav Acha says that Ploni pardoned the lien from the first date. Even if it was a gift, which has no Acharayos, Ploni pardons his rights of Bar Metzra (if an adjacent field was sold in the interim) and allows creditors who lent in the interim to collect the field. If the giver ate the Peros in the interim, Ploni pardons this. Why do we assume that Ploni pardoned a matter that causes him a loss? Perhaps he heard that the giver made a Moda'ah about the first gift (told witnesses that he was being coerced, and the gift is invalid). Rabbeinu Meir says that the Halachah follows Rav Acha. Since it is a Safek whom we follow, the witnesses and Ploni keep their Chezkas Kashrus (they are not established to forge). We establish the land in Ploni's Reshus from the first date regarding Peros and taxes. We do not overturn Ploni's Chazakah due to Safek.

Poskim

Shulchan Aruch (CM 240:2): If both are sale documents or both are gifts, if the latter adds anything, the first is valid. The latter was written just for the addition. If the latter does not add anything, it is Mevatel the former. The Acharayos is only from the latter date. Therefore, Ploni must return all Peros he ate in the interim.

Gra (9): The Shulchan Aruch rules like Rafram.

Question (Beis Yosef DH ul'Inyan): The Rosh and Ramban rule like Rav Acha. The Rambam rules like Rafram, because we leave land in its Chazakah. Why did the Tur omit this?

Objection (Darchei Moshe 1 and Bach DH Mi): The Tur explicitly rules like the Rambam! Even though the Tur says that the seller receives the Peros, even if Ploni ate them he must pay for them (Bach).

Answer #1 (to objection - Keneses ha'Gedolah 10, brought in Hagahos Tur ha'Shalem 3): The Beis Yosef asks why the Tur omitted the Rosh's opinion.

Answer (#2, and also to question - Drishah 1 DH Mi): If the Rambam rules like Rafram, because we leave land in its Chazakah, why didn't he mention that the witnesses are disqualified for Ploni? It seems that the Rambam, like the Rosh, was unsure whom we follow. Both agree that the witnesses keep their Chezkas Kashrus. However, the Rambam says that we leave the land in the Chazakah of the original owner, and the Rosh says that it stays by Ploni (he is Muchzak due to the first document). The Tur rules like the Rosh, but he holds that Peros that were not eaten go to the seller or giver. Ploni pardoned the lien, and all the more so intact Peros! The Tur did not say that witnesses are disqualified. This implies that they are still Kesherim.

Shulchan Aruch (ibid.): If there are property taxes on the property, the giver or seller pays them until the second date.

SMA (1): Even if Ploni paid the tax, he collects it back from the give or seller.

SMA (9) and Drishah (1 DH v'Hinei): The Tur did not mention taxes because nowadays most land does not have taxes; the Rambam and Shulchan Aruch say 'if there are taxes...' Alternatively, when Ploni did not eat the Peros it is obvious that the seller pays the tax. Even Rav Acha would agree!