GEN1483 It would seem to be permitted to deceive someone who has deceived you, in order to undo the damage. … According to an ancient tradition – which Torah law later incorporated – since both of Shelah’s brothers had been childless at the time of their deaths, [Judah] was obligated to marry Tamar. … Tamar, who was legally forbidden to marry any other man, set out to deceive and seduce Judah into sleeping with her … [s]he did this because she did not want to be left both unmarried and forever childless.   The biblical text clearly sees Tamar’s act of deception as a legitimate act of self-defense on her part (indeed, Perez, the older of the twin sons who resulted from this act of deception, became an ancestor of King David, and thus of Judaism’s messianic line). Judah himself recognized that Tamar’s act was justified.   When he learned of her deception, he declared Genesis 38:26, “She is more righteous than I.” TELVOL1:435-6