Do not have sexual relations with your father's wife's daughter

'The nakedness of your father's wife's daughter, born to your father, she is your sister, you shall not uncover her nakedness.

Hebrew

יא עֶרְוַת בַּת-אֵשֶׁת אָבִיךָ מוֹלֶדֶת אָבִיךָ, אֲחוֹתְךָ הִוא--לֹא תְגַלֶּה, עֶרְוָתָהּ. {ס}

Greek

11 ἀσχημοσύνην θυγατρὸς γυναικὸς πατρός σου οὐκ ἀποκαλύψεις· ὁμοπατρία ἀδελφή σού ἐστιν, οὐκ ἀποκαλύψεις τὴν ἀσχημοσύνην αὐτῆς.

• Parashah: Acharei Mot
• Sefer HaChinuch: 196
• Mishneh Torah: Holiness — Forbidden Sexual Relations

• Leviticus 18:11

Enumeration and classification from BibleData. The Greek is the Septuagint reading of the same verse, carried by the source for comparison.