Zerah (which means "scarlet") was one of the twin children of Judah and Tamar. The midwife who was doing the delivery of the two children saw a hand stick out and assumed that this was the first child, so they tied a scarlet string around the hand. Then the hand pulled back in, and the child's brother came out, to which the midwife said, "How hast thou broken forth? this breach be upon thee."  And so that child's name was Perez ("breach"). Soon afterward, the child with the scarlet string on his hand also came out, and was named Zerah.