Sayyiduna Abu Umamah (may Allah be pleased with him) narrates: A man asked, "O Messenger of Allah! What is meant by faith?" The Prophet (peace and blessings be upon him) said: "When your good deeds please you and your bad deeds displease you, then you are a believer." He asked, "O Messenger of Allah! What is sin?" The Prophet (peace and blessings be upon him) said: "When something pricks your heart, then leave it."