أَسْتَغْفِرُ اللَّهَ أَسْتَغْفِرُ اللَّهَ أَسْتَغْفِرُ اللَّهَ
Astaghfirullah, Astaghfirullah, Astaghfirullah
I seek Allah's forgiveness (three times).
The very first thing the Prophet ﷺ would say after giving the salam in prayer — before any other dhikr. Three times. You just finished standing before Allah, bowing, prostrating — yet the first thing you say is "forgive me." Why? Because no prayer is perfect. Your mind wandered, your khushu' wavered, your standing was imperfect. Istighfar after prayer is humility about the quality of your worship.
Related Du'as
أَسْتَغْفِرُ اللَّهَ أَسْتَغْفِرُ اللَّهَ أَسْتَغْفِرُ اللَّهَ اللَّهُمَّ أَنْتَ السَّلَامُ وَمِنْكَ السَّلَامُ تَبَارَكْتَ يَا ذَا الْجَلَالِ وَالْإِكْرَامِ
I seek Allah's forgiveness (three times). O Allah, You are Peace and from You is peace. Blessed are You, O Owner of Majesty and Honor.
Sahihلَا إِلَٰهَ إِلَّا اللَّهُ وَحْدَهُ لَا شَرِيكَ لَهُ لَهُ الْمُلْكُ وَلَهُ الْحَمْدُ وَهُوَ عَلَى كُلِّ شَيْءٍ قَدِيرٌ، اللَّهُمَّ لَا مَانِعَ لِمَا أَعْطَيْتَ وَلَا مُعْطِيَ لِمَا مَنَعْتَ وَلَا يَنْفَعُ ذَا الْجَدِّ مِنْكَ الْجَدُّ
There is no deity except Allah, alone without partner. His is the dominion and His is the praise, and He is over all things capable. O Allah, none can withhold what You have given, and none can give what You have withheld, and no wealth or might can benefit anyone against You.
Sahihاللَّهُمَّ أَعِنِّي عَلَى ذِكْرِكَ وَشُكْرِكَ وَحُسْنِ عِبَادَتِكَ
O Allah, help me to remember You, to thank You, and to worship You in the best manner.
Sahihاللَّهُمَّ إِنِّي أَعُوذُ بِكَ مِنَ الْكُفْرِ وَالْفَقْرِ وَعَذَابِ الْقَبْرِ
O Allah, I seek refuge in You from disbelief, poverty, and the punishment of the grave.
Sahih