Musnad Ahmad Hadith 25508

It is narrated from Aisha (may Allah be pleased with her) that in the last part of his life, the Prophet (ﷺ) used to frequently say: "Subhan Allah wa bihamdihi, astaghfirullaha wa atubu ilayh" (Glory be to Allah and with His praise, I seek forgiveness from Allah and turn to Him in repentance). Once I said, "O Messenger of Allah! I hear you reciting these words frequently, is there a reason for this?" The Prophet (ﷺ) replied, "My Lord informed me that I would see a sign among my Ummah, and He commanded me that when I see that sign, I should glorify Allah with His praise and seek His forgiveness, for He is Most Accepting of Repentance. And I have seen that sign." Then the Prophet (ﷺ) recited the entire Surah: "When the help of Allah and the victory comes, and you see the people entering Allah’s religion in crowds..."