Hadith: The Messenger of Allah (may Allah’s peace and blessings be upon him) would frequently say in his Rukū‘ and prostration: Glory and praise be to You, our Lord. O Allah, forgive me

عن عائشة رضي الله عنها قالت: ما صلّى رسول الله صلى الله عليه وسلم بعد أن نَزَلت عليه: (إذا جاء نصرُ الله والفتح..) إلا يقول فيها: «سُبْحَانَكَ اللهم ربَّنا وبحمدك، اللَّهُمَّ اغفر لي». وفي لفظ: كان رسول الله صلى الله عليه وسلم يكثر أن يقولَ في ركوعه وسجوده: «سُبْحَانَكَ اللَّهُمَّ ربنا وبحمدك، اللَّهُمَّ اغْفِرْ لي».
[صحيح] - [متفق عليه]

‘Ā’ishah (may Allah be pleased with her) reported: The Messenger of Allah (may Allah’s peace and blessings be upon him) did not offer a prayer after the revelation of {When there comes the victory of Allah and the conquest} [Sūrat An-Nasr] except that he would say therein: "Glory and praise be to You, our Lord. O Allah, forgive me!" In another version: "c2">“The Messenger (may Allah's peace and blessings be upon him) would frequently say in his Rukū‘ and prostration: ‘Glory and praise be to You, our Lord. O Allah, forgive me!’”
Sahih/Authentic. - [Al-Bukhari and Muslim]

Explanation

In this Hadīth, ‘Ā’ishah (may Allah be pleased with her) relates that when Allah, the Almighty, revealed Sūrat An-Nasr to His Prophet (may Allah's peace and blessings be upon him) and he saw this sign, the victory and the conquest of Makkah, the Prophet did promptly implement the command of his Lord, frequently repeating: "c2">“Glory and praise be to You, our Lord. O Allah, forgive me!” In these few words, Allah is exalted far above all deficiencies, His praiseworthy traits are mentioned, and His forgiveness is sought. Ever since, the Prophet (may Allah's peace and blessings be upon him) would not perform a prayer, obligatory or voluntary, without saying these words in its bowing and prostration. This Sūrah was a sign of the Prophet's imminent death.