Muwatta Malik Book 7, Hadith 13
Yahya related to me from Malik from Nafi and Abdullah ibn Umar
that a man asked the Messenger of Allah, may Allah bless him and grant
him peace, about night prayers. The Messenger of Allah, may Allah
bless him and grant him peace, said, "Night prayers are two by two,
and when you are afraid that dawn is approaching, pray one raka to
make what you have prayed odd."
Yahya related to me from Malik from Abdullah ibn Abi Bakr from his father that Abdullah ibn Qays ibn Makhrama told him that Zayd ibn Khalid al-Juhani said one night that he was going to observe the prayer of the Messenger of Allah, may Allah bless him and grant him peace. He said, "I rested my head on his threshold. The Messenger of Allah, may Allah bless him and grant him peace, got up and prayed two long, long, long rakas. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed two rakas which were slightly less long than the two before them. Then he prayed an odd raka, making thirteen rakas in all."
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.' "