Tamar

Tamar was given in marriage to Judah's firstborn son Er, who died without children. Custom required Judah's second son Onan to father a child with her to continue Er's line, but Onan refused and also died. Judah sent Tamar back to her father's house with a promise to give his third son Shelah when he was grown — a promise he did not keep, fearing Shelah would die too.

Years later, when Judah's wife died, Tamar learned he was traveling to Timnah. She removed her widow's clothes, veiled herself, and sat by the road where he would pass. Judah took her for a prostitute and slept with her, leaving his personal seal and cord as a pledge for payment. When it became known she was pregnant, Judah ordered her burned for immorality — until she produced his seal and cord. Judah said, "She is more righteous than I, since I did not give her to my son Shelah." She bore twins, Perez and Zerah. Perez became an ancestor of Boaz, then David, and ultimately Jesus (Mat 1:3). Tamar's determination to claim what was rightfully hers made her an unexpected link in the Messianic chain.