حَدَّثَنَا عَفَّانُ حَدَّثَنَا شُعْبَةُ عَنْ أَبِي إِسْحَاقَ قَالَ سَمِعْتُ أَبَا عُبَيْدَةَ عَنْ أَبِيهِ قَالَ كَانَ النَّبِيُّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يُكْثِرُ أَنْ يَقُولَ سُبْحَانَكَ اللَّهُمَّ وَبِحَمْدِكَ اللَّهُمَّ اغْفِرْ لِي فَلَمَّا نَزَلَتْ إِذَا جَاءَ نَصْرُ اللَّهِ وَالْفَتْحُ قَالَ سُبْحَانَكَ اللَّهُمَّ وَبِحَمْدِكَ اللَّهُمَّ اغْفِرْ لِي إِنَّكَ أَنْتَ التَّوَّابُ
مسند امام احمد بن حنبل · Hadith 3891
It was narrated that Abu Ishaq said: I heard Abu 'Ubaidah narrate that his father said: The Prophet (PBUH) often used to say: "O Allah, glory and praise be to You; O Allah, forgive me." When the soorah "When there comes the Help of Allah (to you, O Muhammad (PBUH) against your enemies) and the Conquest (of Makkah)" [an-Nasr 110:1] was revealed, he started saying: "O Allah, glory and praise be to You; O Allah, forgive me; for You are the Acceptor of repentance."
Sanad
حَدَّثَنَا عَفَّانُ حَدَّثَنَا شُعْبَةُ عَنْ أَبِي إِسْحَاقَ قَالَ سَمِعْتُ أَبَا عُبَيْدَةَ عَنْ أَبِيهِ