Genesis 38:27-29
38:27 When it was time for her to give birth, there were twins in her womb.
38:28 While she was giving birth, one child put out his hand, and the midwife took a scarlet thread and tied it on his hand, saying, “This one came out first.”
38:29 But then he drew back his hand, and his brother came out before him. She said, “How you have broken out of the womb!” So he was named Perez.