In the book of Ezekiel, the prophet has a vision of a valley full of dry bones. This vision is interpreted to mean the restoration of the whole house of Israel. The dry bones represent the sinful and disobedient Israelites and Judeans who had been exiled and were scattered among the nations. The vision indicates that God will breathe new life into them and restore them to their land as a united and faithful people. Thus, the expression "dry bones" refers to the sinful Israelites and Judeans who will be restored by God.