My Lord, forgive me and accept my repentance. You are the Accepter of repentance — Gatherings
رَبِّ اغْفِرْ لِي وَتُبْ عَلَيَّ إِنَّكَ أَنْتَ التَّوَّابُ الرَّحِيمُ
Transliteration: Rabbigh-fir lee wa tub 'alayya innaka antat-tawwaabur-raheem
Translation: My Lord, forgive me and accept my repentance. You are the Accepter of repentance, the Merciful. (Said frequently in a gathering)
Reference: Abu Dawud 2:85, Tirmidhi 5:516