Joshua 2:17-21

And the men said unto her, We will be blameless of this thine oath which thou hast made us swear. Behold, when we come into the land, thou shalt bind this line of scarlet thread in the window which thou didst let us down by: and thou shalt bring thy father, and thy mother, and thy brethren, and all thy father's household, home unto thee. And it shall be, that whosoever shall go out of the doors of thy house into the street, his blood shall be upon his head, and we will be guiltless: and whosoever shall be with thee in the house, his blood shall be on our head, if any hand be upon him. And if thou utter this our business, then we will be quit of thine oath which thou hast made us to swear. And she said, According unto your words, so be it. And she sent them away, and they departed: and she bound the scarlet line in the window.