Sanhedrin 84A

וערל בשר לא יבוא אל מקדשי (לשרתני)״.

or uncircumcised in flesh may enter My Temple” (Ezekiel 44:9).

אונן מנלן? דכתיב: ״ומן המקדש לא יצא ולא יחלל את מקדש אלהיו״. הא אחר שלא יצא, חילל.

The Talmud asks: From where do we derive that it is prohibited for an acute mourner priest to perform the Temple service? It is derived from a verse, as it is written with regard to a High Priest whose mother or father died: “And from the Temple he should not emerge and he should not desecrate the Temple of his God” (Leviticus 21:12), from which it may be inferred that another, who is not a High Priest but an ordinary priest, who did not emerge from the Temple and who continued to perform the service, has desecrated the service.

אמר ליה רב אדא לרבא: ונילף ״חילול״ ״חילול״ מתרומה, מה להלן במיתה ⁠– אף כאן במיתה.

Rav Adda said to Rava: And let us derive it by means of a verbal analogy: Derive the meaning of the term of desecration written with regard to an acute mourner who performs the Temple service from the term of desecration written with regard to an impure priest who partakes of teruma. Just as there, with regard to teruma, he is punished with death at the hand of Heaven, so too here, with regard to an acute mourner who performs the Temple service, he is punished with death at the hand of Heaven.

מי כתיב ביה בגופיה? מכללא קאתי. הוי דבר הבא מן הכלל, וכל דבר הבא מן הכלל אין דנין אותו בגזרה שוה.

Rava answers: Is desecration written with regard to the matter of a priest who performs the Temple service as an acute mourner itself? It is derived from that which is written with regard to the High Priest, by inference. Therefore, it is a matter that emerges from an inference, and the principle is: Any matter that emerges from an inference cannot be derived by means of a verbal analogy. A verbal analogy can be derived only when the matter is written explicitly.