"O Messenger of Allah, what do you think I should say in my supplication, if I come upon Laylatul-Qadr?" He said: "Say: 'Allahumma innaka 'afuwwun tuhibbul-'afwa, fa'fu 'anni (O Allah, You are Forgiving and love forgiveness, so forgive me).'" (Using translation from Ibn Mājah 3850)   

قُلْتُ يَا رَسُولَ اللهِ إِنَّ عَلِمْتُ أَيُّ لَيْلَةٍ لَيْلَةُ الْقَدْرِ مَا أَقُولُ فِيهَا؟ قَالَ قَوْلِي «اللهُمَّ إِنَّكَ عَفُوٌّ تُحِبُّ الْعَفْوَ فَاعْفُ عَنِّي»  

[Machine] Narrated Aisha: I said to the Prophet ﷺ , "If I come across Laylat al-Qadr (the Night of Decree), what should I supplicate?" He said, "You should supplicate: 'Allahumma innaka 'afuwwun tuhibbul 'afwa fa'fu 'anni' which means 'O Allah, You are Most Forgiving, and You love forgiveness, so forgive me.'" I was informed by Muhammad ibn Abdul A'la, who narrated from Al-Mu'tamir, who said, "I heard a whisper from Ibn Buraydah that Aisha said, 'O Messenger of Allah, one who is sent.'"  

عَنْ عَائِشَةَ قُلْتُ لِلنَّبِيِّ ﷺ إِنْ وَافَقْتُ لَيْلَةَ الْقَدْرِ مَا أَقُولُ؟ قَالَ تَقُولِينَ اللهُمَّ إِنَّكَ عَفُوٌّ تُحِبُّ الْعَفْوَ فَاعْفُ عَنِّي 10644 أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الْأَعْلَى قَالَ حَدَّثَنَا الْمُعْتَمِرُ قَالَ سَمِعْتُ كَهْمَسًا عَنِ ابْنِ بُرَيْدَةَ أَنَّ عَائِشَةَ قَالَتْ يَا نَبِيَّ اللهِ مُرْسَلٌ  

"O Messenger of Allah, what do you think I should say in my supplication, if I come upon Laylatul-Qadr?" He said: "Say: 'Allahumma innaka 'afuwwun tuhibbul-'afwa, fa'fu 'anni (O Allah, You are Forgiving and love forgiveness, so forgive me).'" (Using translation from Ibn Mājah 3850)   

أَنَّهَا قَالَتْ يَا رَسُولَ اللهِ أَرَأَيْتَ إِنْ وَافَقْتُ لَيْلَةَ الْقَدْرِ مَاذَا أَدْعُو بِهِ؟ قَالَ قَوْلِي اللهُمَّ إِنَّكَ عَفُوٌّ تُحِبُّ الْعَافِيَةَ فَاعْفُ عَنِّي