It was narrated that Farwah bin Nawfal said: "I asked 'Aishah: 'Tell me of something that the Messenger of Allah (ﷺ) used to say in his supplication.' She said: 'The Messenger of Allah (ﷺ) used to say: Allahumma, inni a'udhu bika min sharri ma 'amiltu wa min sharri ma lam a'mal ba'd (O Allah, I seek refuge with You from the evil of what I have done and from the evil of what I have not done.)'"
Source: sunnah.com
Other translations
Arabic
أَخْبَرَنَا مُحَمَّدُ بْنُ عَبْدِ الأَعْلَى، قَالَ حَدَّثَنَا الْمُعْتَمِرُ، عَنْ أَبِيهِ، عَنْ حُصَيْنٍ، عَنْ هِلاَلِ بْنِ يِسَافٍ، عَنْ فَرْوَةَ بْنِ نَوْفَلٍ، قَالَ سَأَلْتُ عَائِشَةَ فَقُلْتُ حَدِّثِينِي بِشَىْءٍ، كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَدْعُو بِهِ قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَقُولُ " اللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ شَرِّ مَا عَمِلْتُ وَمِنْ شَرِّ مَا لَمْ أَعْمَلْ " .
sunnah.com