Genesis 38:24–30

About three months later, Judah was told, “Your daughter-in-law Tamar has prostituted herself, and now she is pregnant.” “Bring her out!” Judah replied. “Let her be burned to death!”

As she was being brought out, Tamar sent a message to her father-in-law: “I am pregnant by the man to whom these items belong.” And she added, “Please examine them. Whose seal and cord and staff are these?”

Judah recognized the items and said, “She is more righteous than I, since I did not give her to my son Shelah.” And he did not have relations with her again.

When the time came for Tamar to give birth, there were twins in her womb.

And as she was giving birth, one of them put out his hand; so the midwife took a scarlet thread and tied it around his wrist. “This one came out first,” she announced.

But when he pulled his hand back and his brother came out, she said, “You have broken out first!” So he was named Perez.

Then his brother came out with the scarlet thread around his wrist, and he was named Zerah.