Sources: the Tanakh and the Talmud; answered in English in the Essay style.

The Answer in Brief

The Torah prescribes the death penalty for adultery. [Leviticus 20:10] states plainly: "If a man commits adultery with a married woman—committing adultery with another man's wife—the adulterer and the adulteress shall be put to death." Both parties are liable. The Talmud refines this: the default mode of execution for a married adulterer and adulteress is strangulation, though stoning applies to a betrothed woman, and burning applies to the married daughter of a priest. [Targum Jonathan on Leviticus 20:10] specifies strangulation by a hard towel and stoning for betrothal cases. The Talmud in [Sanhedrin 52b:22] further clarifies that a minor who commits adultery before reaching legal majority is excluded from liability. Additionally, [Yevamot 24b:11] rules that adulterers who are caught by witnesses can never subsequently marry each other. The prophetic literature frames adultery as a profound moral and covenantal betrayal, comparable to the sins of Sodom.

Background

Adultery in biblical and rabbinic law is defined specifically as sexual intercourse between a married (or betrothed) woman and a man who is not her husband. The biblical category is asymmetrical in one important respect: a married man who has relations with an unmarried woman is not technically guilty of adultery in the same legal sense, because the prohibition centers on the violation of another man's marital bond. The question as posed—"what would happen if I cheated on my wife"—triggers the full weight of the adultery laws only if the other party is a married woman; however, the sources here treat the adulterous man as equally liable to death alongside the woman.

The primary biblical source is [Leviticus 20:10], which sits within the holiness code of Leviticus. This section enumerates capital sexual offenses, and adultery heads the list. The verse uses a double formulation—"a man who commits adultery with a married woman, committing adultery with his neighbor's wife"—which the Talmud reads not as redundancy but as a vehicle for legal derivations.

The Talmud discusses adultery primarily in tractate Sanhedrin, which organizes capital punishments into four categories: stoning, burning, strangulation, and beheading. The default execution for adultery between a married man and a married woman is strangulation—considered by most opinions to be less severe than stoning or burning. The severity of the punishment shifts depending on the status of the woman: betrothed (erusin, the formal first stage of Jewish marriage), married (nissuin), or a priest's daughter. Each status carries a different mode of execution.

The sotah procedure, outlined in Numbers 5, is a related but distinct institution: it addresses the case where a husband suspects infidelity but there are no witnesses. The suspected wife undergoes a ritual ordeal involving bitter waters. Several sources here touch on the sotah context, particularly [Numbers 5:13] and [Sotah 27a:10], though these are tangential to the direct capital law question.

The prophets—Hosea, Jeremiah, and Ezekiel—use adultery as a metaphor for Israel's betrayal of God, but also condemn literal adultery as a social and moral catastrophe. These texts provide the ethical and theological framing around the legal material.

The Sources

The Core Biblical Prohibition

[Leviticus 20:10] is the foundational text: "If a man commits adultery with a married woman—committing adultery with another man's wife—the adulterer and the adulteress shall be put to death." The verse is unambiguous. Both the man and the woman are equally sentenced. The double phrasing—"commits adultery with a married woman" and then "with another man's wife"—is not stylistic repetition. The Talmud will mine this doubling for legal content.

[Onkelos Leviticus 20:10], the Aramaic translation of the Torah by Onkelos (a standard authoritative targum), renders this verse with close fidelity: "A man who commits adultery with another man's wife who commits adultery with the wife of his fellow man—they shall surely be put to death—the adulterer and the adulteress." Onkelos preserves the bilateral liability—both the man and the woman die—without adding new legal content. Its value is confirmatory: the plain meaning of the verse was understood in the Aramaic tradition exactly as it reads in Hebrew.

The Mode of Execution

[Targum Jonathan on Leviticus 20:10] goes significantly further than Onkelos. This later, more expansive Aramaic targum reads: "And the man who by adultery defileth the wife of (another) man, or who committeth adultery with the wife of his married neighbour, shall be verily put to death, by strangulation, with the hard towel in the tender part (?): and on account of a betrothed person, by the casting of stones: both the adulterer and the adulteress (shall die)." Targum Jonathan is already harmonizing the biblical verse with rabbinic legal discussion. It specifies that the default execution is strangulation—carried out by wrapping a hard cloth around the throat—and that if the woman is betrothed rather than fully married, the punishment shifts to stoning. This distinction maps precisely onto the Talmudic discussions in Sanhedrin.

[Sanhedrin 50a:1] and [Sanhedrin 50a:22] address the hierarchy of execution modes. The Gemara states: "The Rabbis hold that only the married daughter of a priest who committed adultery is singled out from all those who commit adultery, for burning." This means the married daughter of a priest faces the most severe execution—burning—while an ordinary married adulteress faces strangulation. [Sanhedrin 50a:22] explains the logic: "Since the Merciful One singles out the case of the married daughter of a priest who committed adultery from the category of a married Jewish woman who committed adultery, changing her punishment from execution by strangulation to execution by burning, conclude from it that burning is more severe than strangulation." The hierarchy, then, is: burning (most severe) > stoning > strangulation (least severe of the three capital modes discussed here).

[Sanhedrin 50b:4] confirms the stoning-strangulation hierarchy from the other direction: "Since the Merciful One singles out the case of the betrothed daughter of a non-priest who committed adultery from the category of a married Jewish woman who committed adultery, changing her punishment from execution by strangulation to execution by stoning, conclude from it that stoning is more severe." The betrothed woman—not yet fully married—receives the harsher punishment of stoning, while the fully married woman receives strangulation.

[Sanhedrin 53a:10] states this principle directly: "From the fact that the Merciful One states that a betrothed woman who committed adultery is executed by stoning, by inference we learn that a married woman who committed adultery is not executed by stoning, but rather she is executed by a less severe type of execution." The less severe execution is strangulation.

[Ketubot 48b:13] provides a practical case that illustrates the boundary between betrothal and marriage: "If the father delivered his daughter to the husband's messengers and she subsequently committed adultery, she is sentenced to strangulation, in accordance with the halakha of a married woman who committed adultery, rather than stoning, which is the punishment for a betrothed woman who commits adultery." The moment the woman transitions from betrothal to marriage—even before the wedding ceremony is complete—the applicable execution shifts from stoning to strangulation. This demonstrates how carefully the rabbis tracked legal status.

[Sanhedrin 50b:13] records a dissenting view: "Rabbi Shimon says: Two general halakhot are stated in the Torah with regard to the daughter of a priest, one rendering the betrothed daughter of a priest who committed adultery liable..." Rabbi Shimon holds a different position on the priest's betrothed daughter, but the details extend beyond the core question here.

Who Is Liable: The Exclusion of Minors

[Sanhedrin 52b:22] provides an important limitation: "The Sages taught: The verse states: 'And a man who commits adultery with another man's wife, even he who commits adultery with his neighbor's wife, both the adulterer and the adulteress shall be put to death' (Leviticus 20:10). The term: 'A man,' is interpreted as excluding a minor boy who committed adultery before he came of age." The word "man" (ish) in the verse is not superfluous; it is exegetically precise. A boy who has not yet reached legal majority (bar mitzvah, generally age thirteen) is excluded from capital liability for adultery. The same verse that condemns the adult adulterer to death simultaneously exempts the minor. This is a standard rabbinic hermeneutical move: inclusive language is read as exclusive by specifying its outer boundary.

[Kiddushin 19a:4] cites the same verse in a different legal discussion: "Rabbi Zeira said: Come and hear a solution to this dilemma from the verse: 'And the man who commits adultery with the wife of another man, even he that commits adultery with his neighbor's wife, both the adulterer and the adulteress shall surely be put to death.'" Rabbi Zeira invokes the verse to resolve a separate halakhic question, demonstrating that the adultery verse in Leviticus 20:10 functions as a proof-text in multiple Talmudic contexts beyond the direct question of execution mode.

The Adulterers Cannot Marry Each Other

[Yevamot 24b:11] addresses what happens after adultery is established by witnesses: "If it is referring to a case where there are witnesses to their adultery, when another came and put an end to the rumor of her misconduct by marrying her, what of it? If there were witnesses, the adulterers may never marry each other." Even if the husband dies or divorces the woman, the adulterer who was caught by witnesses is permanently forbidden from marrying the woman with whom he committed adultery. This is a distinct legal consequence layered on top of the capital punishment: even in a world where the death penalty is not enforced, the adulterous relationship cannot be legitimized through marriage.

Suspicion Without Witnesses: The Sotah Procedure

[Numbers 5:13] describes the case where adultery is suspected but unwitnessed: "A man lay with her, and it was hidden from the eyes of her husband, and she was concealed, and she became defiled, and there is no witness against her and she was not caught." This is the entry point for the sotah (suspected adulteress) ritual. [Sotah 28a:22] notes that the Torah distinguishes between intentional and unintentional adultery in this context: "the Torah does not consider unwitting adultery like intentional adultery, and rape is not treated like a willing transgression." A woman who was coerced is not treated as a willing adulteress.

[Sotah 27a:10] contains a Talmudic discussion comparing the husband and wife in the sotah case, deriving from [Numbers 5:29] that certain physical conditions (blindness, lameness) affect whether the ordeal can be administered. This is peripheral to the core capital question but illustrates how extensively the rabbis analyzed adultery law.

The Prophetic Dimension

[Hosea 4:2] lists adultery among a cascade of social sins: "False swearing, dishonesty, and murder, and theft and adultery are rife; crime follows upon crime." Adultery here is not merely a private wrong but a symptom of total social and covenantal collapse. [Sanhedrin 41a:15] touches on the procedural requirement of forewarning before execution, noting that without forewarning, witnesses can claim their intention was merely to forbid the woman to her husband rather than to execute her—a reminder that capital cases in rabbinic law required extremely precise procedural conditions.

[Chullin 13b:1] delivers a sharp social consequence: "his sons are mamzerim, as he is indifferent to his wife's engaging in adultery." A man who knowingly permits or is indifferent to his wife's adultery produces children whose legal status as mamzerim (a category of prohibited lineage with severe marriage restrictions for many generations) reflects the gravity of the violation.

Where They Agree and Disagree

The sources converge completely on the most fundamental point: adultery between a married man and a married woman is a capital offense, and both parties are equally liable. [Leviticus 20:10], its Onkelos translation, Targum Jonathan, and the Talmudic discussions in Sanhedrin and Kiddushin all affirm this without dissent.

The disagreements are in the details of execution mode. The majority rabbinic position holds that a married adulteress is executed by strangulation, a betrothed woman by stoning, and the married daughter of a priest by burning. [Sanhedrin 50a:1], [50a:22], [50b:4], and [53a:10] collectively establish this framework. Rabbi Shimon, recorded in [Sanhedrin 50b:13], holds a divergent position regarding the priest's betrothed daughter, though the sources here do not fully elaborate his reasoning.

There is also a procedural tension worth noting. [Sanhedrin 41a:15] raises the problem of forewarning: capital punishment in rabbinic law required that the perpetrators be warned immediately before the act. Without this forewarning, the witnesses' testimony could not result in execution but could still result in the woman being forbidden to her husband. This effectively meant that in practice, the death penalty for adultery was almost never carried out—the procedural bar was extremely high. The legal discussion of execution modes thus functioned more as theoretical jurisprudence than as a regularly applied criminal sentence.

The prophetic sources ([Hosea 4:2]) and the legal sources agree that adultery is among the gravest offenses, but the prophets frame the harm in covenantal and communal terms, while the legal texts focus on individual liability and procedural precision. These are complementary rather than contradictory framings.

Conclusion

The Jewish legal tradition answers the question with striking directness. Adultery with a married woman carries the death penalty for both parties under biblical law [Leviticus 20:10], with the mode of execution—strangulation, stoning, or burning—determined by the woman's precise marital status and lineage. The rabbis in Sanhedrin refine these distinctions carefully. Beyond execution, a witnessed adulterer is permanently forbidden from marrying his partner in the offense [Yevamot 24b:11], and a man whose indifference enables his wife's adultery bears consequences extending to the status of his children [Chullin 13b:1]. In practice, the death penalty required procedural conditions so demanding that it was rarely if ever carried out; but the legal framework communicates the weight of the transgression. The prophets reinforce this: adultery belongs to a list of offenses that signal the unraveling of the moral and covenantal order [Hosea 4:2].

References

1. Leviticus.20:10
2. Onkelos Leviticus.20:10
3. Sanhedrin.52b:22
4. Kiddushin.19a:4
5. Targum Jonathan on Leviticus.20:10
6. Ketubot.48b:13
7. Sanhedrin.50a:22
8. Sanhedrin.53a:10
9. Sanhedrin.50b:4
10. Sanhedrin.50a:1
11. Sanhedrin.50b:13
12. Yevamot.24b:11
13. Sotah.28a:22
14. Nedarim.91b:5
15. Jeremiah.23:14
16. Ezekiel.16:32
17. Numbers.5:29
18. Numbers.5:13
19. Sotah.27a:10
20. Sotah.23b:14
21. Hosea.2:4
22. Ezekiel.16:45
23. Chullin.13b:1
24. Hosea.4:2
25. Sanhedrin.41a:15