Musnad Ahmad 1153:1490

'Ali ibn 'Asim narrated to us, Dawud narrated to us, from al-Sha'bi, from Masruq, from 'Aishah, who said: The Messenger of Allah, peace and blessings of Allah be upon him, used to frequently say before his death: "Glory be to Allah and by His praise, I seek forgiveness from Allah, and I repent to Him." She said: And he used to say it frequently. So I said: O Messenger of Allah, you are supplicating with a supplication that you were not supplicating with before today. He said: "Indeed, my Lord, the Almighty and Majestic, informed me that I would see a sign in my nation, and that when I saw that sign, I should glorify Him with His praise and seek His forgiveness. And I have seen that: {When the victory of Allah has come and the conquest, and you see the people entering into the religion of Allah in multitudes} [An-Nasr: 1-2]."