Saved from Danger:

It is stated in the Meshilta (Parshas Hachodesh, Parshah 11): The pasuk states (Devarim 27:6): “With complete (shleimus) stones you shall build." Rav Yochanan ben Zakai said that this means stones that create shalom (because korbanos brought on the stones of the Mizbeach atone for sins and thereby make peace between the nation and Hashem). This is a kal v’chomer. If stones, which cannot see, hear or speak, make peace, and Hashem says that no iron shall be used on them, it is certain that if a person creates peace between a man and his wife or between one city and another, or one family and another, that no danger shall fall upon him.