Bava Metzia 56B

קדשים שהוא חייב באחריותן ⁠– יש להן אונאה. ושאינו חייב באחריותן ⁠– אין להן אונאה. רבי יהודה אומר: אף המוכר ספר תורה, בהמה ומרגלית ⁠– אין להם אונאה. אמרו לו: לא אמרו אלא את אלו.

With regard to sacrificial animals for which one bears responsibility to replace them, they are subject to the halakhot of exploitation, as this responsibility indicates a certain aspect of ownership. And those for which one does not bear responsibility to replace them, they are not subject to the halakhot of exploitation. R' Yehuda says: Even in the case of one who sells a Torah scroll, an animal, or a pearl, these items are not subject to the halakhot of exploitation, as they have no fixed price. The Rabbis said to him: The early rabbis stated that only these items listed above are not subject to the halakhot of exploitation.

גמ׳ מנהני מילי? דתנו רבנן: ״וכי תמכרו ממכר לעמיתך או קנה מיד עמיתך״, דבר הנקנה מיד ליד. יצאו קרקעות, שאינן מטלטלים. יצאו עבדים, שהוקשו לקרקעות. יצאו שטרות, דכתיב: ״וכי תמכרו ממכר״, שגופו מכור וגופו קנוי. יצאו שטרות, שאין גופן מכור ואין גופן קנוי, ואינן עומדין אלא לראיה שבהם.

Talmud: The Talmud asks: From where are these matters derived? It is as A baraita states: It is written: “And if you sell to your colleague an item that is sold, or acquire from your colleague’s hand, one should not exploit his brother” (Leviticus 25:14). This is referring to an item acquired from hand to hand. Land is excluded, as it is not movable. Slaves are excluded, as they are juxtaposed to land in several sources, and therefore their legal status is like that of land in certain respects. Documents are excluded, as it is written: “And if you sell to your colleague an item that is sold,” indicating an item that is itself sold and itself acquired. Documents are excluded, as they are not sold themselves and they are not acquired themselves. They have no intrinsic value, and they exist only for the proof therein.