It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that once the Prophet (peace and blessings be upon him) said: The night prayer consists of two rak‘ahs at a time, and when you fear that morning is near, then add one rak‘ah to these two. And Sayyiduna Ibn Umar (may Allah be pleased with them both) himself would also perform one rak‘ah of Witr.