אֵשֶׁת אָבִיו וְאֵשֶׁת בְּנוֹ וְאֵשֶׁת אָחִיו וְאֵשֶׁת אֲחִי אָבִיו אַרְבַּעְתָּן עֶרְוָה עָלָיו לְעוֹלָם. בֵּין מִן הָאֵרוּסִין בֵּין מִן הַנִּשּׂוּאִין. בֵּין שֶׁנִּתְגָּרְשׁוּ בֵּין שֶׁלֹּא נִתְגָּרְשׁוּ. בֵּין בְּחַיֵּי בַּעְלֵיהֶן בֵּין אַחַר מִיתַת בַּעְלֵיהֶן. חוּץ מֵאֵשֶׁת אָחִיו שֶׁלֹּא הִנִּיחַ בֵּן. וְאִם בָּא עַל אַחַת מֵהֶן בְּחַיֵּי בַּעְלָהּ חַיָּב שְׁתַּיִם. מִשּׁוּם שְׁאֵר בָּשָׂר וּמִשּׁוּם אֵשֶׁת אִישׁ. שֶׁהֲרֵי שְׁנֵיהֶן הָאִסּוּרִין בָּאִין כְּאֶחָד:
The [following] four women: the wife of a man's father, the wife of his son, the wife of his brother, and the wife of the brother of his father, are considered an ervah for him forever, whether after consecration or after marriage, in the lifetime of their husbands or after their deaths, [even] if they were divorced - with the exception of the wife of one's brother who did not leave a son. If a man engages in relations with one of these woman during the lifetime of their husbands, he is liable for two [sin-offerings]: for incestuous relations and adulterous relations, for both of these prohibitions take effect at the same time.
