“O Allah, do not call me to account for what they say and forgive me for what they have no knowledge of [and make me better than they imagine].”
اللَّهُمّ لاَ تُؤاَخِذْنِي ِبَما يَقُولُونُ ، وَاغْفِرْ لِي مَالا يَعْلَمُونَ [وَاجْعَلْنِي خَيْراً مِمَّا َيظُنُّونَ]
Allaahumma laa tu’aakhithnee bimaa yaqooloona, waghfir lee maa laa ya’lamoona [waj’alnee khayram-mimmaa yadhunnoon]
Al-Bukhari, Al-‘Adabul-Mufrad no. 761. See Al-Albani, Sahih Al-‘Adabul-Mufrad (no. 585). The portion between brackets if from Al-Bayhaqi, Shu’ab Al-Iman 4/228