Abu Salamah bin Abd al-Rahman (may Allah have mercy on him) said: I asked Sayyidah Aishah (may Allah be pleased with her): How was the prayer of the Prophet (peace and blessings be upon him) in Ramadan? She said: He (peace and blessings be upon him) did not pray more than eleven rak'ahs, in Ramadan or outside it. He (peace and blessings be upon him) would pray four rak'ahs, and do not ask about their beauty and length; then he would pray four rak'ahs, and do not ask about their beauty and length; then he would pray three rak'ahs. Sayyidah Aishah (may Allah be pleased with her) said: I said: O Messenger of Allah (peace and blessings be upon him), do you (peace and blessings be upon him) sleep before praying witr? He (peace and blessings be upon him) said: "O Aishah, my eyes sleep, but my heart remains awake."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب النكاح / 13386