וְאִ֗ישׁ אֲשֶׁ֤ר יִנְאַף֙ אֶת־אֵ֣שֶׁת אִ֔ישׁ אֲשֶׁ֥ר יִנְאַ֖ף אֶת־אֵ֣שֶׁת רֵעֵ֑הוּ מֽוֹת־יוּמַ֥ת הַנֹּאֵ֖ף וְהַנֹּאָֽפֶת׃
И человек, который совершает прелюбодеяние с другим человеком'жена, даже тот, кто совершает прелюбодеяние со своим соседом'жена, как прелюбодей, так и прелюбодейка, непременно должны быть преданы смерти.
Shenei Luchot HaBerit
מות יומת הנואף והנואפת . The reason why both adulterer and adulteress are to be executed by suffocation (20,10), a relatively easy death penalty, may be connected to what the Torah writes elsewhere concerning the type of death penalty to be administered to a murderer. For a person who murdered another with one single stroke (or bullet causing instant death), the Torah legislated death by suffocation; he presumably did not make his victim suffer. There is no reason therefore to impose a harsher type of execution on the adulterer.