Prayer (Kitab Al-Salat): Detailed Injunctions about Witr
Dawud :: Book 8 : Hadith 1441
Narrated Someone who prayed with the Prophet:
Muhammad ibn Sirin said: Someone who prayed the morning prayer along with the Prophet (peace_be_upon_him) narrated to me: When he raised his head after the second rak'ah, he remained standing for a short while.