Mishnayos Bechoros Perek 9 Mishnah 8

This is the reading: יצאו שנים כאחד מונה אותן שנים שנים מנאן אחד, תשיעי ועשירי מקולקין – if two [animals] came out as one (i.e., at the same time) one next to the other at the width of the opening and he counted them as one pair, he counts all of them two by two, pair-by-pair, and the tenth pair is holy with the sanctity of tithing. And the same law applies if he counted them by threes or by fours.

מנאן אחד – to the first two [animals] that came out he counted as one, and to the third, is the second and to the fourth is the third.

תשיעי ועשירי מקולקלין – because the ninth according to his counting is really the tenth, and the tenth according to his counting is really the eleventh, and because of this, they are spoiled and they should be put out to pasture until they develop a blemish. But this is not similar to calling the tenth – the ninth or the eleventh – the tenth, for the tenth is a tithe and the eleventh is offered as peace offering, for there, it came out one by one, and when he reached the tenth and called it the ninth, and to the eleventh and he called it the tenth, he confirms to the entire world that the ninth according to his counting is the tenth of the animals/cattle, and that the tenth is the eleventh, but he himself changed and erred, therefore, the tenth is a complete tithe, and the eleventh is offered as a peace offering from the decree of the King, as we explain further on. But here, when two went out [of the corral/pen] and he did not make it clear that it was the tenth, that he calls it the ninth, which is the tenth, it is not a complete tithing of its own, as he himself also stated that it is not, therefore, they are spoiled.

שלשתן מקודשים – as it is written (Leviticus 27:32): “All tithes of the herd [or flock],” to include the ninth and the eleventh. It is possible that I also include even the eighth and the seventh. You said, for since and it is holy (see the end of Leviticus 27:32), and his error is sanctified, what is not holy is only that which is near/next to it, meaning to say, the tenth itself which is next to it/adjacent to its body, even his error is not sanctified other than which is adjacent/next to the tenth – which is the ninth from before it and the eleventh from after it.

וכי יש תמורה עושה תמורה – Rabbi Yehuda holds that this eleventh [animal] is a substitute, for that which he called the “tenth” is considered like that which is in place of the tenth, but there is no substitute which imparts the status of a substitute to another, as it is written (Leviticus 27:33): “then it and its substitute shall both be holy” – but not the substitution of the substitution.

אמרו משום רבי מאיר – it is not a substitution. The eleventh is not a substitution for the tenth. For if it was a substitution, it would not be offered as a sacrifice, for the substitution of the tithe is not offered, as it is written (Numbers 18:17): “[But the firstlings of cattle, sheep, or goats] may not be redeemed; they are consecrated. [You shall dash their blood against the altar, and turn their fat into smoke as a pleasing odor to the LORD],” they are offered as sacrifices, but not their substitutions, and it is written concerning firstlings, and we derive tithes from it. And the Halakha is that the eleventh does not become a substitution/replacement.

כל שלא נעקר שם עשירי ממנו – wherever that he called the tenth the tenth, furthermore, he cannot advance the eleventh for what he called the tenth [which was not deprived of its proper name].