Genesis 38:27-30

And it came to pass in the time of her travail, that, behold, twins were in her womb. And it came to pass, when she travailed, that one put out a hand: and the midwife took and bound upon his hand a scarlet thread, saying, This came out first. And it came to pass, as he drew back his hand, that, behold, his brother came out: and she said, Wherefore hast thou made a breach for thyself? therefore his name was called Perez. And afterward came out his brother, that had the scarlet thread upon his hand: and his name was called Zerah.