On account of her faith and hospitality, Rahab the harlot was saved. For when spies were sent by Joshua, the son of Nun, to Jericho, the king of the country ascertained that they were come to spy out their land, and sent men to seize them, in order that, when taken, they might be put to death. But the hospitable Rahab receiving them, concealed them on the roof of her house under some stalks of flax. And when the men sent by the king arrived and said “There came men unto thee who are to spy out our land; bring them forth, for so the king commands,” she answered them, “The two men whom ye seek came unto me, but quickly departed again and are gone,” thus not discovering the spies to them. Then she said to the men, “I know assuredly that the Lord your God hath given you this city, for the fear and dread of you have fallen on its inhabitants. When therefore ye shall have taken it, keep ye me and the house of my father in safety.” And they said to her, “It shall be as thou hast spoken to us. As soon, therefore, as thou knowest that we are at hand, thou shall gather all thy family under thy roof, and they shall be preserved, but all that are found outside of thy dwelling shall perish.” 53 Moreover, they gave her a sign to this effect, that she should hang forth from her house a scarlet thread. And thus they made it manifest that redemption should flow through the blood of the Lord to all them that believe and hope in God. 54 Ye see, beloved, that there was not only faith, but prophecy, in this woman.
Others of the Fathers adopt the same allegorical interpretation, e.g., Justin Mar., Dial. c. Tryph., n. 111; Irenæus, Adv. Hær., iv. 20. [The whole matter of symbolism under the law must be more thoroughly studied if we would account for such strong language as is here applied to a poetical or rhetorical figure.]