'Thread' in the Bible

that I will take nothing belonging to you, not even a thread or the strap of a sandal. That way you can never say, 'It is I who made Abram rich.'

While she was giving birth, one child put out his hand, and the midwife took a scarlet thread and tied it on his hand, saying, "This one came out first."

Afterward his brother came out -- the one who had the scarlet thread on his hand -- and he was named Zerah.