once
اللَّهُمَّ إِنِّي أَسْأَلُكَ بِرَحْمَتِكَ الَّتِي وَسِعَتْ كُلَّ شَيْءٍ أَنْ تَغْفِرَ لِي
Edition transliteration
Allahumma inne as-aluka birahmatikal-latee wasiAAat kulla shay, an taghfira lee.
Meaning
O Allah, I ask You by Your mercy which envelopes all things, that You forgive me.
Source and references
Hisn al-Muslim, entry 177.The reference is copied from the edition; separate editorial verification is not complete yet.
Source edition: Fortress of the Muslim. Open source ↗