Gemara

(Mishnah): If a woman wrote to the buyer 'I have no claim against you' (she cannot collect her Kesuvah from what he bought).

Contradiction (Beraisa): If a man wrote to his friend (or partner) 'I have no claim or dealings in this field', these words are void.

Answer: The case is, they acquired the waiving of her rights (through Chal, i.e. transferal of a garment).

(Mishnah): One cannot collect from sold land when the debtor still has Bnei Chorin (unsold property), even if it is Ziburis (lowest quality land).

Question: If the Bnei Chorin were flooded, may the creditor take sold land?

Answer #1 (Beraisa - R. Meir): If a man sold two fields, and his wife signed only on the second, she (pardoned her lien and) lost her Kesuvah.

If a creditor can take sold land when Bnei Chorin are flooded, granted she cannot take from the second buyer, but she should take from the first!

Rejection #1 (Rav Nachman bar Yitzchak): The Beraisa says that she lost her Kesuvah, i.e. the right to take from the second buyer. She can take from the first!

Objection #1 (Rava): 'She lost her Kesuvah' connotes that she lost it entirely.

Objection #2 (Rava - Beraisa): A man borrowed from one man, and sold property to two men. The creditor wrote to the second buyer, I have no claim against you. He cannot take from the first buyer, for the first buyer can tell him, I left for you property from which to collect!

There, he overtly caused his own loss.

Answer #2 (Rav Yemar): In everyday practice, creditors take from sold property when the Bnei Chorin are flooded!

E.g. a certain lender took a vineyard for 10 years (the produce would pay off the debt). After five years, it stopped producing. Chachamim ruled that he can take property that the borrower had sold.

Rejection (Rav Ashi): There, the buyers caused their own loss. They should have realized that vineyards often stop producing, and refrained from buying the other property.

The Halachah is, if the Bnei Chorin are flooded, the creditor may take sold land.

Gitin 50b - Question (Rav Achdevoy bar Ami): Do we say that one cannot collect from a gift (just like one cannot take from buyers) if there are Bnei Chorin?

If the enactment was so that buyers should not lose, if a gift is taken, the receiver did not lose, so no enactment was made;

Or, perhaps we say that surely, the receiver benefited the giver. If he loses the gift, this is like a loss!

Answer (Mar Kashisha - Beraisa): If a Shechiv Mera said 'give 200 Zuz to Reuven, after him, 300 to Shimon, and after him, 400 to Moshe', they collect in the order of the documents. Therefore, if a creditor collects from the estate, he takes from Moshe. If Moshe does not have enough, he takes from Shimon...

Even if Reuven received Beinonis, and Moshe received Ziburis, the loan is collected from the Ziburis (for this was the borrower's last Bnei Chorin).

This shows that the enactment was made also regarding gifts!

Rejection #1: No. The case is, Reuven, Shimon and Moshe did not get gifts. They were creditors being paid up!

Rejection #2: Really, a creditor takes Beinonis no matter who received it. The Beraisa discusses taking from Moshe, for he always suffers the loss (if anyone's land is taken, he is compensated by latter recipients).

Rejection #3: The Beraisa discusses when all lands are the same quality. (If they were not, the creditor would receive Beinonis, no matter who has it!)

Rishonim

Rif and Rosh (Gitin 25a and 5:2): One cannot take from sold land when the debtor has Bnei Chorin. A gift is like a sale. We learn from a Shechiv Mera who gave gifts in order. A creditor takes from the last recipient first, even if he received Ziburis and the first received Beinonis. This teaches that the enactment applies to gifts. The rejections of the proof are flimsy; we do not rely on them. The Halachah is, if the Bnei Chorin are flooded, the creditor takes sold land.

Ran (Kesuvos 55a DH Garsinan): The Rashba says that if an extortionist seized the Bnei Chorin, one may not take sold land. Thugs are prone to fall, so the creditor will eventually collect the Bnei Chorin.

Rambam (Hilchos Malveh 18:1): If David lends to Levi Stam, all Levi's property has Acharayos and is an Arev (guarantor) for the loan. Therefore, if Levi has Metaltelim or land, David collects with Levi's consent, or if not, through Beis Din. If the property does not suffice to pay the document, David collects from all land that Levi owned, even if now it is sold to others or given for gifts. Since Levi sold or gave after incurring this debt, David takes from the buyers or recipients.

Kesef Mishneh: He must collect from Levi first because sold property is only an Arev. One must claim from the borrower before claiming from the Arev.

Rambam (19:2): One may not take from sold land when the debtor still has Bnei Chorin, even if the Bnei Chorin are Beinonis and the sold land is Ziburis. If the Bnei Chorin were flooded, the creditor may take sold land. Since they were destroyed, it is as if there are none.

Rosh (10:17): Rashi explains that Rava said 'there, he (or she) overtly caused his (her) own loss' (by pardoning the lien). This rejects Rav Nachman's answer. R. Tam explains that these words are part of Rav Nachman's answer. The creditor knew that he would need to collect; he caused his own loss! We do not blame a wife, for it was not clear that she would ever get to collect her Kesuvah.

Poskim

Shulchan Aruch (CM 111:8): One may takes from buyers only if he does not find Bnei Chorin with the borrower. If he finds Bnei Chorin, he cannot take sold land, even if the Bnei Chorin are Beinonis and the sold land is Ziburis. We do not distinguish between sold land and land given for a gift.

SMA (14): The creditor must take Ziburis because this is the law mid'Oraisa. Chachamim enacted that creditors receive Beinonis lest people be deterred from lending. They did not decree when it will cause buyers to lose.

Note: Also damages are not collected from sold land if the damager still has Bnei Chorin, even if they are Ziburis (Rambam Hilchos Nizkei Mamon 8:11), even though mid'Oraisa damages are collected from highest quality land!

Beis Yosef (DH ba'Meh): Sefer ha'Terumos says that even if the orphans sold their father's property, it is considered sold property and creditors cannot take from it if there are Bnei Chorin.

Shulchan Aruch (12): If buyers left Bnei Chorin with the borrower, and the Bnei Chorin became ruined, the lender can take from buyers. This is only if they were ruined. If the lender cannot collect due to his negligence, e.g. he released his lien through a Kinyan, he cannot take from buyers. They can say 'we left property for you to collect.'

Shach (8): R. Chananel, R. Tam and the Rosh hold that a woman would collect (Bnei Chorin) in such a case.

Gra (25): The Gemara said that a woman must do Chalipin to waive her rights. The same applies to a creditor.