Musnad Abu Ya'la al-Mawsili 159:29

Abu Khaythama narrated to us, Sufyan narrated to us, from Abu al-Zinad, from al-A'raj, from Abu Hurayrah, who said: "To Allah belong ninety-nine names, one hundred minus one. Whoever preserves them enters Paradise. And He is Witr (Odd/One), He loves the Witr."