ויקרא, פרק כ׳, פסוק י״ד

A situation where a man becomes intimately involved with both a woman and her mother, or her daughter, represents a profound level of depravity. When two women sharing such close blood ties occupy the mind and life of a single man, it reflects a complete immersion in lust and impurity [ביאור שטיינזלץ]. The Hebrew root for this type of depravity implies deep thought and calculated planning [מלבי״ם, אבן עזרא]. Because natural human inclination does not typically desire close family members, committing such an act is not a momentary lapse of passion but a deliberate, malicious choice meant to anger God [שפתי כהן].

This severe decree is specifically tied to the framework of marriage. The restriction and its corresponding punishment take effect only if the man's first relationship was established through lawful matrimony. If he merely seduced or forced himself upon a woman, her relatives are not subsequently forbidden to him under this specific penalty [מלבי״ם, אדרת אליהו, פירושי רד״צ הופמן]. While the primary example given is a woman and her mother, commentators agree that this law extends across three generations in either direction, encompassing relationships with a daughter, granddaughter, mother-in-law, or wife's grandmother [תורה תמימה, חזקוני, רש״ר הירש].

The consequence for this profound violation is death by burning. However, this does not refer to being consumed by an external fire. Instead, it is described as a process that burns the soul while leaving the body intact. This was carried out by pouring molten metal into the condemned person, a method chosen to directly strike the internal organs associated with the lust that drove the sin [רלב״ג, רש״ר הירש, פירושי רד״צ הופמן].

A significant question arises regarding who exactly is subjected to this punishment, as the phrasing suggests that the man is to be burned along with both women. This presents a moral difficulty, since the first woman was married legally and committed no wrong. The primary approach among commentators resolves this by explaining that the original text incorporates a borrowed Greek term meaning "one", indicating that only the man and the single woman involved in the forbidden relationship are punished [רש״י, בכור שור, מזרחי]. A simpler explanation suggests the plural form is used because the punishment could fall on either woman depending on the chronological order of the marriages. If the man married the mother first, the daughter is punished, and vice versa [בכור שור, חזקוני].

Taking a different approach, another perspective argues that the plural phrasing is not meant to punish both women, but rather to establish a condition for the penalty. The severe punishment of burning is only administered to the man and the second woman if both women are alive at the time the sin is committed. If the first wife has already passed away, the severity of the offense is reduced and the penalty of burning is not applied [מזרחי, תורה תמימה, הכתב והקבלה]. An unusual viewpoint suggests that the first wife is indeed punished, but only if she knew her husband had taken her relative and willingly chose to remain in the marriage [שד״ל]. However, this idea is strongly rejected by others, who point out that a woman lacks the power to divorce her husband against his will, and therefore cannot be held responsible for his actions [אם למקרא].

Ultimately, the goal of this severe consequence is to completely eradicate such impurity and uproot deeply corrupted thoughts from the holy camp of the Israelites, ensuring that the community maintains its sanctity [פירושי רד״צ הופמן, ביאור שטיינזלץ].