It is narrated from Sayyiduna Ibn Umar (may Allah be pleased with them both) that once a Bedouin asked the Prophet (peace and blessings be upon him) about the night prayer, so the Prophet (peace and blessings be upon him) gestured with his two fingers and said: "Pray two rak‘ahs at a time, and the witr is one rak‘ah in the last part of the night."