Abdullah bin Umar (may Allah be pleased with them both) narrated: A man came to the Messenger of Allah (peace and blessings be upon him) and asked: O Messenger of Allah! How is the night prayer (to be performed)? He replied: "Two by two (rak‘ahs); when you fear that dawn is about to break, then pray one rak‘ah as witr, which will make your (previous) prayer odd."