Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Sa’d bin Abi Waqqas (may Allah be pleased with him) that he used to perform the ‘Isha prayer in the Prophet’s Mosque and after that, he would only pray one rak‘ah of Witr. He was asked: “Abu Ishaq! You only pray one rak‘ah of Witr and do not perform any more prayers (what is the reason)?” He replied: “Yes, I myself heard the Messenger of Allah (peace and blessings be upon him) say: ‘That servant is cautious (and prudent) who performs Witr before sleeping.’”