It was narrated that ‘Asim bin Humaid said:“I asked ‘Aishah: ‘With what did the Prophet (ﷺ) start voluntary prayers?’ She said: ‘You have asked me about something which no one has asked before. He used to say Allahu Akbar ten times, and Al-Hamdu Lillah ten times and Subhan Allah ten times, and he would say Allahumma aghfirli wahdini, warzuqni, wa ‘afini (O Allah, forgive me, guide me, grant me provision and give me good health),” and he would seek refuge from the difficulty of the standing on the Day of Resurrection.”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا زَيْدُ بْنُ الْحُبَابِ، عَنْ مُعَاوِيَةَ بْنِ صَالِحٍ، حَدَّثَنِي أَزْهَرُ بْنُ سَعِيدٍ، عَنْ عَاصِمِ بْنِ حُمَيْدٍ، قَالَ سَأَلْتُ عَائِشَةَ مَاذَا كَانَ النَّبِيُّ ـ صلى الله عليه وسلم ـ يَفْتَتِحُ بِهِ قِيَامَ اللَّيْلِ قَالَتْ لَقَدْ سَأَلْتَنِي عَنْ شَىْءٍ مَا سَأَلَنِي عَنْهُ أَحَدٌ قَبْلَكَ كَانَ يُكَبِّرُ عَشْرًا وَيَحْمَدُ عَشْرًا وَيُسَبِّحُ عَشْرًا وَيَسْتَغْفِرُ عَشْرًا وَيَقُولُ " اللَّهُمَّ اغْفِرْ لِي وَاهْدِنِي وَارْزُقْنِي وَعَافِنِي " . وَيَتَعَوَّذُ مِنْ ضِيقِ الْمُقَامِ يَوْمَ الْقِيَامَةِ .
IbnMaja
Establishing the Prayer and the Sunnah Regarding Them • Hadith 1356