Gittin 21B

לא אפשר למקצייה, אלא קרן של פרה ⁠– ליקצייה וליתבה לה!

it is not possible to cut it off, as it is certainly prohibited to cut off the hand of a slave, and he therefore must give her the slave. But if he wrote the bill of divorce on the horn of a cow, let him cut it off and give it to her. Why does the Mishnah state that he must give her the cow?

אמר קרא: ״וכתב״⁠ – ״ונתן לה״, מי שאינו מחוסר אלא כתיבה ונתינה; יצא זה ⁠– שמחוסר כתיבה, קציצה ונתינה.

The Talmud answers: The verse states: “And he writes her a scroll of severance, and gives it in her hand” (Deuteronomy 24:1), meaning that something is valid as a bill of divorce when it is lacking only writing and giving, excluding this, a cow’s horn, which is lacking writing, cutting, and giving. Since the additional step of cutting would be required in order for him to give her the horn alone, the horn would not be a valid bill of divorce, so he must give her the cow.

רבי יוסי הגלילי אומר וכו׳: מאי טעמא דרבי יוסי הגלילי? דתניא: ״ספר״⁠ – אין לי אלא ספר, מנין לרבות כל דבר? תלמוד לומר: ״וכתב לה״⁠ – מכל מקום. אם כן, מה תלמוד לומר ״ספר״? מה ספר ⁠– דבר שאין בו רוח חיים, ואינו אוכל; אף כל דבר ⁠– שאין בו רוח חיים ואינו אוכל.

§ The Mishnah taught that R' Yosei HaGelili says that a bill of divorce may not be written on something living, nor on food. The Talmud asks: What is the reason for R' Yosei HaGelili’s opinion? As it is taught in a baraita: It is said in the Torah with regard to a bill of divorce: “And he writes her a scroll of severance” (Deuteronomy 24:1). From the word “scroll,” I have derived only that a scroll is valid; from where do I derive that it is correct to include all objects as valid materials upon which a bill of divorce may be written? The verse states: “And he writes her,” in any case, i.e., a bill of divorce can be written on any type of surface. If so, what is the meaning when the verse states “scroll”? This teaches: Just as a scroll is neither alive nor food, so too, a bill of divorce may be written on any object that is neither alive nor food. This is why R' Yosei HaGelili deems invalid a bill of divorce written on a living being.