'Thread' in the Bible

That I will not take so much as a thread or the cord of a shoe of yours; so that you may not say, I have given wealth to Abram:

And while she was in the act of giving birth, one of them put out his hand; and the woman who was with her put a red thread round his hand, saying, This one came out first.

And then his brother came out, with the red thread round his hand, and he was named Zerah.