twin sons of
Judah & Tamar
And it came to pass, when she [Tamar] travailed, that the one put out his 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, How hast thou broken forth? this breach be upon thee: therefore his name was called Pharez. And afterward came out his brother, that had the scarlet thread upon his hand: and his name was called Zarah. Genesis 38: 28 - 30