Jami` at-Tirmidhi 439

Sa'eed bin Abi Sa'eed Al-Maqburi narrated that:Sa'eed bin Abi Sa'eed Al-Maqburi narrated that Abu Salamah informed him that he had asked Aishah: "How was the Salat of Allah's Messenger (A) [at night] during Ramadan?" She said: "Allah's Messenger (S) would pray - neither in Ramadan nor in any other month - more than eleven Rak'ah. He would pray four, and do not ask about their excellence or length, then he would pray four, and do not ask about their excellence or length, then he would pray three." Aishah said: "I asked: 'O Messenger of Allah! Do you sleep before having performed Witr?" He said: 'O Aishah! Indeed my eyes sleep but my heart does not sleep