Source and decoding
לעולם כשחייב מודה, והכא היינו טעמא: דחיישינן שמא כתב ללות בניסן ולא לוה עד תשרי, ואתי למטרף לקוחות שלא כדין.
The debtor indeed admits the debt. We fear he wrote the document to borrow in Nisan but did not borrow until Tishrei, and may wrongfully seize property from purchasers.
Borrower admission does not protect purchasers: writing in Nisan and lending in Tishrei could harm intervening land buyers. Loss undermines the document’s standing. Agreement of two parties does not protect a third.