Narrated from ‘Aishah (Radi Allaahu anhu) that she said:
“O Messenger of Allah, what do you think I should say in my supplication, if I come upon Laylat-ul-Qadr (Night of Decree)?” He said: Say –
“Allahumma innaka ‘afuwwun tuhibbul-‘afwa, fa’fu ‘anni”
(O Allah, You are Forgiving and love forgiveness, so forgive me).
Grade: Sahih (Darussalam); Reference: Sunan Ibn Majah 3850; In-book reference: Book 34, Hadith 24; English translation: Vol. 5, Book 34, Hadith 3850.
Other Links: https://sunnah.com/riyadussaliheen/9/205