“Peace be upon you.” The Prophet explained: “Whenever a man says “Peace and God's Mercy be upon you” to another man, it means that he has pledged to God not to gossip about him, not to find faults in what he says, not to seek his faults. Whenever the other man responds by saying “And peace and God's Mercy and His Blessings be upon you”, it means that he makes the same pledge to God plus hoping for God's Mercy upon you, and also takes God as a witness to them.”