Shurahbil bin Simt narrates: Once, Sayyiduna Salman (may Allah be pleased with him) passed by him while he was standing guard. Sayyiduna Salman (may Allah be pleased with him) asked: "Shurahbil, what are you doing here?" Shurahbil replied: "I am standing guard." Sayyiduna Salman (may Allah be pleased with him) said: "I heard the Noble Prophet (peace and blessings be upon him) say: 'One day (the narrator is unsure, perhaps these are the words) or one night of standing guard is better than fasting for a month and performing voluntary prayers.'"