לֹ֣א יַחֲלִיפֶ֗נּוּ וְלֹֽא־יָמִ֥יר אֹת֛וֹ ט֥וֹב בְּרָ֖ע אוֹ־רַ֣ע בְּט֑וֹב וְאִם־הָמֵ֨ר יָמִ֤יר בְּהֵמָה֙ בִּבְהֵמָ֔ה וְהָֽיָה־ה֥וּא וּתְמוּרָת֖וֹ יִֽהְיֶה־קֹּֽדֶשׁ׃
On ne peut ni le changer ni le remplacer, bon, par un défectueux, défectueux, par un meilleur; si toutefois on avait remplacé cet animal par un autre, l’animal et son remplaçant seront également saints.
Sefer HaMitzvot
He prohibited us from substituting consecrated animals. And that is His saying, "One may not exchange nor substitute for it" (Leviticus 27:10). And the prohibition already appeared specifically about the [animal] tithe. And the reason is that which they mentioned in the [Sifra] (Sifra, Bechukotai, Chapter 9:4): And that is their saying, "The tithe was in the category [of all consecrated animals]. Why, then, was it singled out? To make a comparison to it: Just as the tithe is consecrated animals that go on the altar and its substitution is not permitted; so too, is the substitution of all consecrated animals that go on the altar not permitted." And that is His saying, "nor substitute for it," and His saying, "One may not exchange" - however that is only with consecrated animals that go on the altar. And one who substitutes [it] is lashed. And the regulations of this commandment have already been explained in Temurah. (See Parashat Bechukotai; Mishneh Torah, Substitution 1.)