The Messenger of Allah ﷺ said to al-Abbas ibn AbdulMuttalib: Abbas, my uncle, shall I not give you, shall I not present to you, shall I not donate to you, shall I not produce for you ten things? If you act upon them, Allah will forgive you your sins, first and last, old and new, involuntary and voluntary, small and great, secret and open. These are the ten things: you should pray four rak'ahs, reciting in each one Fatihat al-Kitab and a surah. When you finish the recitation of the first rak'ah you should say fifteen times while standing: "Glory be to Allah", "Praise be to Allah", "There is no god but Allah", "Allah is most great". Then you should bow and say it ten times while bowing. Then you should raise your head after bowing and say it ten times. Then you should kneel down in prostration and say it ten times while prostrating yourself. Then you should raise your head after prostration and say it ten times. Then you should prostrate yourself and say it ten times. Then you should raise your head after prostrating and say it ten times in every rak'ah. You should do that in four rak'ahs. If you can observe it once daily, do so; if not, then once weekly; if not, then once a month; if not, then once a year; if not, then once in your lifetime. (Using translation from Abū Dāʾūd 1297)
أَنَّ رَسُولَ اللَّهِ ﷺ قَالَ لِلْعَبَّاسِ بْنِ عَبْدِ الْمُطَّلِبِ يَا عَبَّاسُ يَا عَمَّاهُ أَلَا أُعْطِيكَ أَلَا أَحْبُوكَ أَلَا أَفْعَلُ بِكَ عَشْرُ خِصَالٍ إِذَا أَنْتَ فَعَلْتَ ذَلِكَ غَفَرَ اللَّهُ لَكَ ذَنْبَكَ أَوَّلَهُ وَآخِرَهُ قَدِيمَهُ وَحَدِيثَهُ خَطَأَهُ وَعَمْدَهُ صَغِيرَهُ وَكَبِيرَهُ سِرَّهُ وَعَلَانِيَتَهُ أَنْ تُصَلِّيَ أَرْبَعَ رَكَعَاتٍ تَقْرَأُ فِي كُلِّ رَكْعَةٍ بِفَاتِحَةِ الْكِتَابِ وَسُورَةٍ فَإِذَا فَرَغْتَ مِنَ الْقِرَاءَةِ فِي أَوَّلِ رَكْعَةٍ قُلْتَ وَأَنْتَ قَائِمٌ سُبْحَانَ اللَّهِ وَالْحَمْدُ لِلَّهِ وَلَا إِلَهَ إِلَّا اللَّهُ وَاللَّهُ أَكْبَرُ خَمْسَ عَشْرَةَ مَرَّةً ثُمَّ تَرْكَعُ فَتَقُولُ وَأَنْتَ رَاكِعٌ عَشْرًا ثُمَّ تَرْفَعُ رَأْسَكَ فَتَقُولُهَا عَشْرًا ثُمَّ تَسْجُدُ فَتَقُولُهَا عَشْرًا ثُمَّ تَرْفَعُ رَأْسَكَ فَتَقُولُهَا عَشْرًا ثُمَّ تَسْجُدُ فَتَقُولُهَا عَشْرًا ثُمَّ تَرْفَعُ رَأْسَكَ فَتَقُولُهَا عَشْرًا فَذَلِكَ خَمْسَةٌ وَسَبْعُونَ فِي كُلِّ رَكْعَةٍ تَفْعَلُ فِي أَرْبَعِ رَكَعَاتٍ إِنِ اسْتَطَعْتَ أَنْ تُصَلِّيَهَا فِي كُلِّ يَوْمٍ فَافْعَلْ فَإِنْ لَمْ تَفْعَلْ فَفِي كُلِّ جُمُعَةٍ مَرَّةً فَإِنْ لَمْ تَفْعَلْ فَفِي كُلِّ شَهْرٍ مَرَّةً فَإِنْ لَمْ تَفْعَلْ فَفِي كُلِّ سَنَةٍ مَرَّةً فَإِنْ لَمْ تَفْعَلْ فَفِي عُمُرِكَ مَرَّةً