After completing salah

أَسْتَغْفِرُ اللَّهَ، اللَّهُمَّ أَنْتَ السَّلَامُ وَمِنْكَ السَّلَامُ تَبَارَكْتَ يَا ذَا الْجَلَالِ وَالْإِكْرَامِ

Astaghfirullah. Allahumma antas-salam wa minkas-salam, tabarakta ya dhal-jalali wal-ikram

I seek Allah’s forgiveness. O Allah, You are Peace and from You is peace. Blessed are You, Possessor of majesty and honour.