Tamar understood she needed to act to secure her family's future. Following the levirate custom (see study note on 38:8), she remained loyal to her dead husband. She had a legal right to have a child with Judah's son or Judah himself. So she tricked her father-in-law into having sexual relations with her. Again, Jacob’s family experiences deception, this time by a Canaanite daughter-in-law.