The courts must carry out the death penalty of burning

If there is a man who marries a woman and her mother, it is immorality; both he and they shall be burned with fire, so that there will be no immorality in your midst.

Hebrew

יד וְאִישׁ, אֲשֶׁר יִקַּח אֶת-אִשָּׁה וְאֶת-אִמָּהּ--זִמָּה הִוא; בָּאֵשׁ יִשְׂרְפוּ אֹתוֹ, וְאֶתְהֶן, וְלֹא-תִהְיֶה זִמָּה, בְּתוֹכְכֶם.

Greek

14 ὃς ἐὰν λάβῃ γυναῖκα καὶ τὴν μητέρα αὐτῆς, ἀνόμημά ἐστιν· ἐν πυρὶ κατακαύσουσιν αὐτὸν καὶ αὐτάς, καὶ οὐκ ἔσται ἀνομία ἐν ὑμῖν.

• Parashah: Kedoshim
• Sefer HaChinuch: 261
• Mishneh Torah: Judges — The Sanhedrin and the Penalties Under Their Jurisdiction

• Leviticus 20:14

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