Sunan an-Nasa'i, Book 50, Hadith 99 (In-Book) ⓘ
It was narrated that 'Aishah said: "The Messenger of Allah [SAW] 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 yet.)'"
أَخْبَرَنَا هَنَّادٌ، عَنْ أَبِي الأَحْوَصِ، عَنْ حُصَيْنٍ، عَنْ هِلاَلٍ، عَنْ فَرْوَةَ بْنِ نَوْفَلٍ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَقُولُ " اللَّهُمَّ إِنِّي أَ عُوذُ بِكَ مِنْ شَرِّ مَا عَمِلْتُ وَمِنْ شَرِّ مَا لَمْ أَعْمَلْ " .
also referenced under: Hadith 5526 (Reference) & Volume 6, Book 50, Hadith 5528 (DarusSalam)