143

Not to have sexual relations with your son's daughter

The Luchos - Ten Commandments
עֶרְוַ֤ת בַּת־בִּנְךָ֙ א֣וֹ בַֽת־בִּתְּךָ֔ לֹ֥א תְגַלֶּ֖ה עֶרְוָתָ֑ן כִּ֥י עֶרְוָתְךָ֖ הֵֽנָּה׃ - פָּרָשַׁת אַחֲרֵי מוֹת
Leviticus 18:10 - "The nakedness of your son's daughter or your daughter's daughter you shall not uncover their nakedness, for they are your own nakedness."

This Mitzvah's Summary

מִצְוָה עֲשֵׂה - Positive Commandment
מִצְוָה לֹא תַעֲשֶׂה - Negative Commandment
Family – מִשְׁפָּחָה

Forbidden to have sexual relations with one’s granddaughter through one’s son.

This mitzvah prohibits sexual relations with one’s granddaughter, the daughter of one’s son. The Torah equates such a relationship with uncovering one’s own nakedness, underscoring the abhorrence of such an act. It is among the most severe prohibitions in the category of arayot (forbidden relations), carrying grave punishment.

Commentary & Classical Explanation:

  • Rambam (Hilchot Issurei Bi’ah 2:8): Includes both paternal and maternal grandchildren in the incest prohibitions.
  • Sefer HaChinuch (Mitzvah 192): The root is to preserve family sanctity and prevent disgraceful relations that would blur generational boundaries.
  • Talmud (Sanhedrin 55b): Notes that this verse includes both a son’s daughter and a daughter’s daughter, as both are considered one’s own nakedness.
(Source: Chabad.org)

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