At least three times, in the Bible, men chosen by God find themselves trapped inside walled cities with enemies pursuing them. In Joshua, the men are the spies, sent by Joshua to spy out Jerico. They do not save themselves after Rahab hides them on the rooftop. It is Rahab, from Christ's lineage, who lowers them through a window, to safety.

The spies did not save themselves. God's provision of Rahab saved them.

Joshua 2:11 And as soon as we had heard these things, our hearts did melt, neither did there remain any more courage in any man, because of you: for the LORD your God, he is God in heaven above, and in earth beneath. Joshua 2:12 Now therefore, I pray you, swear unto me by the LORD, since I have showed you kindness, that ye will also show kindness unto my father's house, and give me a true token: Joshua 2:13 And that ye will save alive my father, and my mother, and my brethren, and my sisters, and all that they have, and deliver our lives from death. Joshua 2:14 And the men answered her, Our life for yours, if ye utter not this our business. And it shall be, when the LORD hath given us the land, that we will deal kindly and truly with thee. Joshua 2:15 Then she let them down by a cord through the window:for her house was upon the town wall, and she dwelt upon the wall. Joshua 2:16 And she said unto them, Get you to the mountain, lest the pursuers meet you; and hide yourselves there three days, until the pursuers be returned: and afterward may ye go your way. Joshua 2:17 And the men said unto her, We will be blameless of this thine oath which thou hast made us swear.