Musnad Ahmad 1153:1084

Yazid narrated to us, he said: Al-Asbagh informed us, from Thawr ibn Yazid, from Khalid ibn Ma'dan, he said: Rabi'ah al-Jurashi narrated to me, he said: I asked Aisha, and I said: "What did the Messenger of Allah, peace and blessings of Allah be upon him, say when he stood up at night? And with what did he begin?" She said: "He would say 'Allahu Akbar' ten times, and 'SubhanAllah' ten times, and 'La ilaha illallah' ten times, and seek forgiveness ten times. And he would say: 'O Allah, forgive me, guide me, and provide for me' ten times. And he would say: 'O Allah, I seek refuge in You from the narrowness of the Day of Reckoning' ten times."