Refuge from something not yet committed
The second half is the unusual one.
أَعُوذُ بِكَ مِنْ شَرِّ مَا عَمِلْتُ وَمِنْ شَرِّ مَا لَمْ أَعْمَلْ
Aʿūdhu bika min sharri mā ʿamiltu wa min sharri mā lam aʿmal
“I seek refuge in You from the evil of what I have done, and from the evil of what I have not done.”
Where this comes from
The first half is the ordinary request. The second covers what he has not done yet, and what he failed to do, in the same four words.
The full narration
It was narrated that Farwah bin Nawfal said:"I asked the Mother of the Believers 'Aishah about what the Messenger of Allah [SAW] used to say in his supplication. She said: 'He used to say: A'udhu bika min sharri ma 'amiltu wa min sharri ma lam a'mal ba'd (I seek refuge with You from the evil of what I have done and the evil of what I have not done yet)
Source
Sunan an-Nasā'ī · 5525
- Abu Ghuddah: Sahih
- Al-Albani: Sahih
- Zubair Ali Zai: Sahih Muslim