Genesis 38:28-30

28And 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. 29But when he pulled his hand back and his brother came out, she said, “You have broken out first!” So he was named Perez.1 30Then his brother came out with the scarlet thread around his wrist, and he was named Zerah.2