Sunan Ibn Majah, Volume 2, Book 5, Hadith 1396 (DarusSalam) ⓘ

It was narrated from ‘Asim bin Sufyan Thaqafi that they went on the campaign of Salasil, but no battle took place; they only took up their positions. Then they came back to Mu’awiyah, and Abu Ayyub and ‘Uqbah bin ‘Amir were with him. ‘Asim said: “O Abu Ayyub, we have missed out on Jihad this year, and we were told that whoever prays in the four mosques will be forgiven his sins.” He said: “O son of my brother, shall I not tell you of something easier than that? I heard the Messenger of Allah say: ‘Whoever performs ablution as he has been commanded, and prays as he has been commanded, will be forgiven his previous (bad) deeds.’” He said: “(Did he not say it) like that, O ‘Uqbah?” He said: “Yes.”

حَدَّثَنَا مُحَمَّدُ بْنُ رُمْحٍ، أَنْبَأَنَا اللَّيْثُ بْنُ سَعْدٍ، عَنْ أَبِي الزُّبَيْرِ، عَنْ سُفْيَانَ بْنِ عَبْدِ اللَّهِ، - أَظُنُّهُ - عَنْ عَاصِمِ بْنِ سُفْيَانَ الثَّقَفِيِّ، أَنَّهُمْ غَزَوْا غَزْوَةَ السَّلاَسِلِ فَفَاتَهُمُ الْغَزْوُ فَرَابَطُوا ثُمَّ رَجَعُوا إِلَى مُعَاوِيَةَ وَعِنْدَهُ أَبُو أَيُّوبَ وَعُقْبَةُ بْنُ عَامِرٍ فَقَالَ عَاصِمٌ يَا أَبَا أَيُّوبَ فَاتَنَا الْغَزْوُ الْعَامَ وَقَدْ أُخْبِرْنَا أَنَّهُ مَنْ صَلَّى فِي الْمَسَاجِدِ الأَرْبَعَةِ غُفِرَ لَهُ ذَنْبُهُ ‏.‏ فَقَالَ يَا ابْنَ أَخِي أَدُلُّكَ عَلَى أَيْسَرَ مِنْ ذَلِكَ إِنِّي سَمِعْتُ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ يَقُولُ ‏ "‏ مَنْ تَوَضَّأَ كَمَا أُمِرَ وَصَلَّى كَمَا أُمِرَ غُفِرَ لَهُ مَا قَدَّمَ مِنْ عَمَلٍ ‏" ‏ ‏.‏ أَكَذَلِكَ يَا عُقْبَةُ قَالَ نَعَمْ ‏.‏