The spies gave their solemn promise to spare Rahab and her household but specified three conditions that Rahab had to meet. [source][source][source]
1.She had to make her home known to the Israelites when they attacked ( Joshua 2:18).2.She had to assemble her family into her home before the battle ( Joshua 2:18).3.She had to keep the mission of the spies a secret ( Joshua 2:20; Joshua 2:14). [source][source][source]
The cord Rahab was to hang out of her window and over the town wall-her house stood on the wall ( Joshua 2:15)-was scarlet in color ( Joshua 2:15; Joshua 2:18). Archaeologists have discovered houses within the ruined walls of ancient Jericho. [1] Its unusual color would have marked Rahab"s house for the Israelites. The color had symbolic significance, too, since red recalls blood and vigorous life. [source][source][source]
"In the preaching of the Christian church, all the way back to Clement of Rome ..., this has been taken as a sign of the blood of Christ, the Lamb." [2][source]
There is no Scriptural statement that the cord is a type, however. [source][source][source]
"It answered, therefore, the same purpose with the blood sprinkled upon the door-posts in Egypt, which secured the first-born from the destroying angel." [3][source]
God spared the lives of Rahab and her household because of her faith. Any of Rahab"s relatives that would have gathered with her before the Israelite siege would have done so because of their faith in God"s promise through the spies. If they had no faith they would have stayed in their own homes. Thus the deliverance of Rahab and her family depended on believing a promise from God. Salvation always depends on believing a promise from God (cf. Genesis 15:6; John 3:16; et al.). [source][source][source]