It was narrated from ‘lkrimah bin Khalid: `Whoever purifies himself as he has been enjoined and prays as he has been enjoined, his sins will be expiated.” Then he called four of the Companions of the Messenger of Allah (ﷺ) to testify to that, and they testified that the Prophet (ﷺ) had said that. Grade: Hasan because of corroborating evidence, this isnad is da‘eef] (Darussalam) Reference : Musnad Ahmad 486 In-book reference : Book 4, Hadith 79

قَالَ حَدَّثَنَا عَفَّانُ، حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ إِبْرَاهِيمَ بْنِ الْمُهَاجِرِ، عَنْ عِكْرِمَةَ بْنِ خَالِدٍ، حَدَّثَنِي رَجُلٌ، مِنْ أَهْلِ الْمَدِينَةِ أَنَّ الْمُؤَذِّنَ، أَذَّنَ لِصَلَاةِ الْعَصْرِ قَالَ فَدَعَا عُثْمَانُ رَضِيَ اللَّهُ عَنْهُ بِطَهُورٍ فَتَطَهَّرَ قَالَ ثُمَّ قَالَ سَمِعْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ يَقُولُ مَنْ تَطَهَّرَ كَمَا أُمِرَ وَصَلَّى كَمَا أُمِرَ كُفِّرَتْ عَنْهُ ذُنُوبُهُ فَاسْتَشْهَدَ عَلَى ذَلِكَ أَرْبَعَةً مِنْ أَصْحَابِ رَسُولِ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ قَالَ فَشَهِدُوا لَهُ بِذَلِكَ عَلَى النَّبِيِّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ‏.‏