Musnad Abu Ya'la al-Mawsili 151:21

Uthman ibn Abi Shaybah narrated to us, Abu Hafs narrated to us, from al-A’mash, from ‘Amr ibn Murrah, from Abu ‘Ubaydah, from ‘Abdullah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Indeed, Allah is Witr (Odd/One) and He loves the Witr, so perform Witr, O people of the Quran." A Bedouin said: "What are you saying, O Messenger of Allah?" He said: "It is not for you, nor for your companions."