Qutayba bin Sa'id bin Jamil قتيبة بن سعيد بن جميل · The Book on Al-Witr

he asked Ibn Umar about the length of the two Rak'ah (before) Al-Fajr. He said: "The Prophet would pray two and two during the night, and he would perform Al-Witr with one Rak'ah. And he would pray two Rak'ah while he was hearing the Adhan ."

"Allah's Messenger taught me some phrases to say during Al-Witr (Allahummahdini fiman hadait, wa a'fini fiman afait, wa tawallani fiman tawallait, wa barik Li fima atait, wa qini sharra ma qadait, fa Innaka taqdi wa la yuqda Alaik, wa innahu la yadhillu man walait, tabarakta Rabbana wa ta'alait.) 'O Allah guide me among those You have guided, pardon me among those You have pardoned, befriend me among those You have befriended, bless me in what You have granted, and save…

the Prophet said: "Whoever sleeps past his Al-Witr then let him pray it in the morning."

"I was with Ibn Umar on a journey and I fell behind him. He said: 'Where were you?' I said: 'I prayed Al-Witr.' He said: 'Is there not a good exampled for you in Allah's Messenger? I saw Allah's Messenger performing Al-Witr on his mount.'"

"Allah's Messenger would teach us Al-Isthikhara for all of our affairs just as he would teach us a Surah of the Qur'an, saying: 'When one of you is worried about a matter, then let him perform two Rak'ah other than the obligatory (prayer), then let him say: (Allahumma inni astakhiruka bi'ilmika, wa astaqdiruka biqudratika, wa as'aluka min falikal-azim, fa innaka taqdiru wa la qadiru, wa ta'lami wa la a'lamu, wa anta allamul-ghayub. Allahumma in kunta ta'lamu anna hadhal-amra khairun li…