Jerome of Stridon
The harlot Rahab, representing the church, displayed the thread that held the secret of the Lord's blood from her window, so that her home would be spared during Jericho's destruction. Similarly, the Scriptures mention the holy ones in this manner: these are... who emerged from the fervor of the household of the father of Rechab (1 Chronicles 2:55).
The harlot Rahab, representing the Church, bound a cord to her window as a sign of the sacrament associated with the shedding of blood, in order to secure her salvation during the fall of Jericho.