The Messenger of Allah ﷺ used to make supplication during the prayer saying: "O Allah, I seek refuge in Thee from the punishment of the grave; I seek refuge in Thee from the trial of the Antichrist; I seek refuge in Thee from the trial of life and the trial of death; O Allah, I seek refuge in Thee from sin and debt." Someone said to him: How often you seek refuge from debt! He replied: When a man is in debt, he talks and tells lies, makes promises and breaks them. (Using translation from Abū Dāʾūd 880)   

أَنَّ عَائِشَةَ زَوْجِ النَّبِيِّ ﷺ أَخْبَرَتْهُ أَنَّ النَّبِيَّ ﷺ كَانَ يُدْعُو فِي الصَّلَاةِ اللهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ عَذَابِ الْقَبْرِ وَأَعُوذُ بِكَ مِنْ فِتْنَةِ الْمَسِيحِ الدَّجَّالِ وَأَعُوذُ بِكَ مِنَ الْمَأْثَمِ وَالْمَغْرَمِ قَالَتْ فَقَالَ لَهُ قَائِلٌ مَا أَكْثَرَ مَا تَسْتَعِيذُ مِنَ الْمَغْرَمِ يَا رَسُولَ اللهِ قَالَ إِنَّ الرَّجُلَ إِذَا غَرِمَ حَدَّثَ فَكَذَبَ وَوَعَدَ فَأَخْلَفَ  

The Messenger of Allah (way peace be upon him) said: When any one of you utters tashahhud (in prayer) he must seek refuge with Allah from four (trials) and should thus say:" O Allah! I seek refuge with Thee from the torment of the Hell, from the torment of the grave, from the trial of life and death and from the evil of the trial of Masih al-Dajjal" (Antichrist). (Using translation from Muslim 588a)   

قَالَ رَسُولُ اللهِ ﷺ إِذَا تَشَهَّدَ أَحَدُكُمْ فَلْيَسْتَعِذْ بِاللهِ مِنْ أَرْبَعٍ يَقُولُ اللهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ عَذَابِ جَهَنَّمَ وَمِنْ عَذَابِ الْقَبْرِ وَمِنْ فِتْنَةِ الْمَحْيَا وَالْمَمَاتِ وَمِنْ فِتْنَةِ الْمَسِيحِ الدَّجَّالِ  

[Machine] The Messenger of Allah ﷺ said, "When one of you finishes his prayer, let him supplicate four du'as, then let him supplicate whatever he wishes. O Allah, I seek refuge in You from the punishment of Hellfire and the punishment of the grave and the tribulation of life and death and the tribulation of the false messiah (Dajjal)."  

قَالَ رَسُولُ اللهِ ﷺ إِذَا فَرَغَ أَحَدُكُمْ مِنْ صَلَاتِهِ فَلْيَدْعُ بِأَرْبَعٍ ثُمَّ لِيَدْعُ بَعْدُ بِمَا شَاءَ اللهُمَّ إِنِّي أَعُوذُ بِكَ مِنْ عَذَابِ جَهَنَّمَ وَعَذَابِ الْقَبْرِ وَفِتْنَةِ الْمَحْيَا وَالْمَمَاتِ وَفِتْنَةِ الْمَسِيحِ الدَّجَّالِ  

Teach me a du'aʿ that I may say in my prayer. He said: ʿSay: O Allah. I have wronged myself greatly and no one forgives sins except You, so grant me forgiveness from You and have mercy on me, for You are the Oft-Forgiving, Most Merciful.ʿ (Using translation from Aḥmad 28)   

أَنَّهُ قَالَ لِرَسُولِ اللهِ ﷺ عَلِّمْنِي دُعَاءً أَدْعُو بِهِ فِي صَلَاتِي قَالَ قُلْ اللهُمَّ إِنِّي ظَلَمْتُ نَفْسِي ظُلْمًا كَثِيرًا وَلَا يَغْفِرُ الذُّنُوبَ إِلَّا أَنْتَ فَاغْفِرْ لِي مَغْفِرَةً مِنْ عِنْدَكَ وَارْحَمْنِي إِنَّكَ أَنْتَ الْغَفُورُ الرَّحِيمُ لَفْظُهُمَا سَوَاءٌ