4929. 'On whose hand was the twice-dyed thread' means the acknowledgement that good is such. This is clear from the fact that he was then acknowledged to be the firstborn because of 'the twice-dyed thread on his hand', thus that it was good which opened the womb or was the firstborn. The midwife binding on his hand a twice-dyed thread means that she provided a sign to indicate which one was the firstborn, and therefore acknowledgement is meant here.