The supplication most often made by the Prophet of Allah ﷺ was, "O Allah, forgive me for what I have done by mistake and what I have done deliberately, what I have concealed and what I have made public, what I did in ignorance and what I did intentionally."
كان عامة دعاء نبي الله ﷺ: اللهم اغفر لي ما أخطأت وما تعمدت، وما أسررت وما أعلنت، وما جهلت وما تعمدت.
Ahmad (19925) and Bazzar (3525) both narrated it through the route of Muaz bin Hisham, who said, Awn bin Abu Shaddad Aqeeli narrated to me, from Mutarrif (who is Ibn Abdullah bin Shikhir), from Imran bin Husayn, and he related it.Its isnad is hasan because of Muaz bin Hisham, who is Dastawai, and likewise Awn bin Abu Shaddad Aqeeli is hasan al-hadith, for Ibn Main deemed him trustworthy and Ibn Hibban mentioned him among the trustworthy narrators.