Genesis 38:27, 29-30

And it came to pass in the time of her travail, that, behold, twins were in her womb.

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.