Bekhorot 60B

קרא לתשיעי ״עשירי״, ולעשירי ״תשיעי״, ולאחד עשר ״עשירי״. תנו רבנן: מנין שאם קרא לתשיעי ״עשירי״, ולעשירי ״תשיעי״, ולאחד עשר ״עשירי״, ששלשתן מקודשין?

§ The Mishnah teaches: If he mistakenly called the 9th: Tenth, and the tenth: 9th, and the 11th: Tenth, all 3 are sacred, although each has a different halakhic status. The Talmud cites a relevant baraita: A baraita states: From where is it derived that if one mistakenly called the 9th animal: Tenth, and the tenth animal: 9th, and the 11th animal: Tenth, that all 3 of them are sanctified?

תלמוד לומר: ״וכל מעשר בקר וצאן כל אשר יעבור תחת השבט העשירי יהיה קדש״, יכול שאני מרבה אף שמיני ושנים עשר?

The verse states: “And all the tithe of the herd or the flock, whatever passes under the rod, the tenth should be sacred to YHWH” (Leviticus 27:32). This indicates that the tenth animal that passes under the rod is imbued with sanctity, in addition to any animal that the owner designates as the tenth. One might have thought that I include even the 8th animal or the 12th animal, if they were mistakenly designated as the tenth.

אמרת: הואיל והוא קדוש, וטעותו מתקדשת, מה הוא אינו מקודש אלא בסמוך, אף טעותו אינה מתקדשת אלא בסמוך.

You said in response that since the tenth animal is sanctified and the animal that he designated by mistake as the tenth is sanctified, their statuses should be compared: Just as the tenth animal is sanctified only with an animal that was close to the number 10, i.e., it itself was the tenth, so too, an animal that was designated by mistake is sanctified only if it is close to the number 10, i.e., if it is the 9th or 11th, but not if it is the 8th or the 12th.

והתניא: מה הוא מיוחד, אף טעותו מיוחדת!

The Mishnah teaches that if one mistakenly designated the 9th and the 11th animals as the tenth they are both sanctified. The Talmud raises a difficulty: But isn’t it taught in a baraita that just as the tenth animal itself is unique, i.e., it is only one, so too, an animal that was designated by mistake is unique, i.e., only one additional animal receives the sanctity, but not both the 9th and the 11th?