Temurah 27A

״ואם תחתיה תעמוד הבהרת״.

“But if the white leprous spot stays in its place [taḥteha]” (Leviticus 13:23). In this verse, the word “taḥteha” indicates that the white leprous spot remains in its place. This usage of the word is fitting for substitution, since when sanctity is transferred by substitution from a consecrated animal to a non-sacred animal, the sanctity of the consecrated animal remains in place, despite the fact that the non-sacred animal is also consecrated.

דאחולי, דכתיב: ״תחת הנחושת אביא זהב״, והלכך, גבי קדשי מזבח דעבדין תמורה ⁠— לישנא דאתפוסי הוא, גבי קדשי בדק הבית דלא עבדין תמורה ⁠— לישנא דאחולי הוא.

Yet taḥat is also a term that indicates desacralization, as it is written: “In place of [taḥat] brass I will bring gold, and in place of iron I will bring silver, and in place of wood brass, and in place of stones iron” (Isaiah 60:17). In this verse, taḥat means replacement, which is what occurs in desacralization, where one item is replaced by another. And therefore, the term should be understood in accordance with the context: With regard to animals consecrated for sacrifice upon the altar, which render a non-sacred animal for which they are exchanged a substitute, taḥat is a term that indicates the associating of one sanctity with another. With regard to animals consecrated for Temple maintenance, which do not render a non-sacred animal for which they are exchanged a substitute, taḥat is a term that indicates desacralization.

אמר רבא: אפילו בקדשי מזבח משכחת לה לישנא דאחולי הוא, כגון שהיה הקדש בעל מום.

Rava said: Even with regard to animals consecrated for sacrifice upon the altar, which render a non-sacred animal for which they are exchanged a substitute, you can find that taḥat is a term that indicates desacralization. For example: in a case where a consecrated animal was blemished and can be desacralized because it is unfit to be sacrificed, and one placed that consecrated animal next to a non-sacred animal and said: This animal is in place of [taḥat] that animal. Although the blemished sacred animal can render a non-sacred animal for which it is exchanged consecrated as a substitute, in this context the term taḥat means desacralization.