פירוש על בבא קמא 15:9

What [would] a person typically bring out? The most inferior of his utensils. Ulo is proving that the creditor is paid with the poorest quality since the Torah says that “the man to whom you lend shall bring out the security to you”. That “man” the borrower, given the choice will bring out the least of his utensils. The Torah is giving that “man” the right to pay with that which he sees fit; obviously he will choose the poorest. Tosafot points out that there is another person involved in the process, the court emissary.
Even though it is the court emissary who brings out the security to the lender, the court emissary only brought out to the lender that which the borrower gave him. The decision of what to give as security remained with the borrower, who would obviously choose the least valuable of his utensils.

To bring out the most inferior of his utensils. The debtor’s right to bring out the least of his utensils is presented as proof that the creditor collects his debt from the poorest by Torah law. The supposition is that the least of the utensils is by definition not the finest. This contradicts what we have learned earlier.
And if you ask: Even the least of utensils is “the finest” as the Gemara said earlier (Bava Kamma 7b), all movable items are the finest since they can be transported to where they are sought after.
And we can answer: When one brings out utensils it is usual for him to bring out the least valuable and so too, when he brings¹A debtor does not actually bring land. What Tosafot means is that he may offer some of his land as security for the debt. He will certainly offer the poorest of his land as the security. land it is also usual that he brings the poorest. Since the Torah places the decision in the hands of the borrower, when he offers land he will offer the poorest which the lender must accept.
It appears that the correct ruling is that qualities are designated according to the debtor’s property, for that is the opinion of R’ Nachmon in Ketubot 110a.²There is a dispute there between Rav Nachman and Rav Shaishes. The Gemara there says that the essence of the dispute is whether we follow world standards or the damager’s private standards, with Rav Nachman’s position being that we follow the individual debtor’s standards. Generally in this type of dispute we follow Rav Nachman.
As was pointed out at the end of Tosafot ה מר לית ליה תקנתא דעולא ' ד, in the fourth and final solution, according to both Braitas the designation of qualities is based on world standards. Tosafot felt the need to say that this is not the halachic ruling, rather we follow R’ Nachmon who holds that designation of qualities is based on the properties of the debtor.