Do not have sexual relations with your son's daughter

'The nakedness of your son's daughter or your daughter's daughter, their nakedness you shall not uncover; for their nakedness is yours.

Hebrew

י עֶרְוַת בַּת-בִּנְךָ אוֹ בַת-בִּתְּךָ, לֹא תְגַלֶּה עֶרְוָתָן: כִּי עֶרְוָתְךָ, הֵנָּה. {ס}

Greek

10 ἀσχημοσύνην θυγατρὸς υἱοῦ σου ἢ θυγατρὸς θυγατρός σου, οὐκ ἀποκαλύψεις τὴν ἀσχημοσύνην αὐτῶν, ὅτι σὴ ἀσχημοσύνη ἐστίν.

• Parashah: Acharei Mot
• Sefer HaChinuch: 193
• Mishneh Torah: Holiness — Forbidden Sexual Relations

• Leviticus 18:10

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