Genesis 38:27-30

When the time came for her to give birth, there were twin boys in her womb. As she was giving birth, one of them put out his hand; so the midwife took a scarlet thread and tied it on his wrist and said, “This one came out first.” But when he drew back his hand, his brother came out, and she said, “So this is how you have broken out!” And he was named Perez. Then his brother, who had the scarlet thread on his wrist, came out. And he was named Zerah.