Sayyiduna Abu Dharr Ghifari (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said to me: Perform the prayer at its (prescribed) time, then when you come to the people and they have already performed the prayer, you have protected your prayer, and if they have not yet performed the prayer, then perform the prayer with them, and it will be a voluntary (nafl) prayer for you.