Muwatta Malik Book 7, Hadith 15
Yahya related to me from Malik from Abu Bakr ibn Umar that Said
ibn Yasar said, ''I was travelling with Abdullah ibn Umar on the road
to Makka, and fearing that it was nearly dawn. I dismounted and prayed
witr. Abdullah said, 'Is there not a model for you in the Messenger of
Allah, may Allah bless him and grant him peace?' I said, 'Of course,
by Allah!' He said, 'The Messenger of Allah, may Allah bless him and
grant him peace, used to pray witr on his camel.' "
Yahya related to me from Malik from Yahya ibn Said from Muhammad ibn Yahya ibn Habban from Ibn Muhayriz that a man from the Kinana tribe called al-Mukhdaji heard a man in Syria known as Abu Muhammad saying, "The witr is obligatory (fard)." Al-Mukhdaji said, "I went to Ubada ibn as-Samit and presented myself to him as he was going to the mosque, and told him what Abu Muhammad had said. Ubada said that Abu Muhammad had lied and that he had heard the Messenger of Allah, may Allah bless him and grant him peace, say, 'Allah the Majestic and Mighty has written five prayers for mankind, and whoever does them and does not waste anything of them by making light of what is due to them, there is a pact for him with Allah that He will admit him into the Garden.Whoever does not do them, there is no pact for him with Allah. If He wishes, He punishes him, and if He wishes, He admits him into the Garden.' "
Yahya related to me from Malik from Yahya ibn Said that Said ibn al-Musayyab said, "Abu Bakr as-Siddiq used to pray witr when he wished to go to bed, and Umar ibn al-Khattab used to pray witr at the end of the night. As for me, I pray witr when I go to bed."