Bekhorot 59B

אף התשיעי אינו קדוש אלא אם כן נעקר שם עשירי הימנו, והדין נותן.

Even the 9th that was accidentall y designated as the tenth is not sanctified and may be eaten before it develops a blemish, unless the name of the tenth is removed from the tenth animal, i.e., if the owner erred also in that he called the tenth animal the 9th. And logical reasoning leads to this conclusion.

ומה אחד עשר שהוא עושה קדושה ליקרב, אינו קדוש אלא אם כן נעקר שם ״עשירי״ הימנו, תשיעי שאין עושה קדושה ליקרב ⁠— אינו דין שאם נעקר שם ״עשירי״ הימנו ⁠— אין, אי לא ⁠— לא?

The Talmud explains the logical reasoning: The halakha is that if one designated the 9th animal as the tenth, and the tenth as the tenth, and the 11th as the tenth, then the 11th is not consecrated. This is because in any situation where the name of the tenth was not removed from the tenth animal, the 11th, which was called the tenth, is not consecrated. And if the 11th animal, which becomes sanctified to be sacrificed as a peace offering, as stated in the Mishnah on 60a, is sanctified only if the name of the tenth is removed from the tenth animal, then with regard to the 9th animal, which does not become sanctified to be sacrificed but is eaten once it develops a blemish, is it not logical that if the name of the tenth is removed from the actual tenth animal, then yes, the 9th animal has sanctity and may be eaten only once it develops a blemish, but if not, then it is not sanctified at all and may be eaten even without a blemish?

היא הנותנת! אחד עשר שהוא עושה קדושה ליקרב, אי נעקר שם עשירי הימנו ⁠— אין, אי לא ⁠— לא; תשיעי שאינו עושה קדושה ליקרב, אף על גב דלא נעקר שם עשירי הימנו.

The Talmud rejects this logical derivation: That claim itself provides support for the contrary opinion. With regard to the 11th animal, which becomes sanctified with a stringent sanctity to be sacrificed as a peace offering, if the name of the tenth is removed from the actual tenth animal, then yes, the 11th becomes sanctified, but if the designation of being the tenth is not removed from the tenth, then the 11th does not become sanctified. But with regard to the 9th animal, which does not become sanctified with the stringent sanctity to be sacrificed, one can say that even though the name of the tenth animal is not removed from the tenth animal, nevertheless the 9th becomes sanctified.