It is narrated from Hazrat Abdur Rahman bin Abzi, may Allah be pleased with him, on the authority of Ubayy bin Ka'b, may Allah be pleased with him, that the Noble Prophet, peace and blessings be upon him, used to recite "Glorify the name of your Lord, the Most High" (Surah Al-A'la), "Say: O disbelievers" (Surah Al-Kafirun), and "Say: He is Allah, the One" (Surah Al-Ikhlas) in Witr prayer, and after concluding the prayer with salam, he would say "Subhanal Malikil Quddus" three times.