Leviticus 20:10

ואיש AND THE MAN [THAT COMMITTETH ADULERY SHALL SURELY BE PUT TO DEATH] — a man, thus excluding a minor (Sifra, Kedoshim, Chapter 10 8). אשר ינאף את אשת איש WHO COMMITTETH ADULTERY WITH ANOTHER MAN'S WIFE — a man's wife, thus excluding the wife of a minor from the death penalty. This teaches us that a minor cannot enter into a marriage contract. And in reference to what married woman do I make you liable to the death penalty? אשר ינאף את אשת רעהו IF HE COMMITTETH ADULTERY WITH THE WIFE OF HIS FELLOW-MAN — his fellow-man, thus excluding the wife of a heathen; this teaches us that a heathen cannot enter into a marriage contract according to Jewish law (Sifra, Kedoshim, Chapter 10 8; Sanhedrin 52b). מות יומת הנאף והנאפת THE ADULTERER AND THE ADULTRESS SHALL SURELY BE PUT TO DEATH — Wherever a death penalty is mentioned in Scripture without being precisely defined, only strangulation is intended (Sifra, Kedoshim, Chapter 10 8; Sanhedrin 55b).

וְאִ֗ישׁ אֲשֶׁ֤ר יִנְאַף֙ אֶת־אֵ֣שֶׁת אִ֔ישׁ אֲשֶׁ֥ר יִנְאַ֖ף אֶת־אֵ֣שֶׁת רֵעֵ֑הוּ מֽוֹת־יוּמַ֥ת הַנֹּאֵ֖ף וְהַנֹּאָֽפֶת׃

And the man that commits adultery with another man’s wife, that commits adultery with his neighbour’s wife, the adulterer and the adulteress shall surely be put to death.