Sunan an-Nasa'i 144

أَخْبَرَنَا قُتَيْبَةُ بْنُ سَعِيدٍ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنْ أَبِي الزُّبَيْرِ، عَنْ سُفْيَانَ بْنِ عَبْدِ الرَّحْمَنِ، 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 صلى الله عليه وسلم يَقُولُ ‏ "‏ مَنْ تَوَضَّأَ كَمَا أُمِرَ وَصَلَّى كَمَا أُمِرَ غُفِرَ لَهُ مَا قَدَّمَ مِنْ عَمَلٍ ‏"‏ ‏.‏ أَكَذَلِكَ يَا عُقْبَةُ قَالَ نَعَمْ ‏.‏

It was narrated from 'Asim bin Sufyan Ath-Thaqafi that they went out for the battle of As-Salasil, but they missed the fighting, so they kept watch, then they went back to Mu'awiyah, and Abu Ayyub and 'Uqbah bin 'Amir were with him. 'Asim said:"O Abu Ayyub, we missed the general mobilization, but we have been told that whoever prays in the four Masjids will be forgiven his sins." He said: "O son of my brother! I will tell you of something easier than that. I heard the Messenger of Allah (ﷺ) says: 'Whoever performs Wudu' as commanded and prays as commanded, will be forgiven for his previous actions.' Is it not so, O 'Uqbah?" He said: "Yes

Reference

Sunan an-Nasa'i 144

In-book

Book 1, Hadith 145