Sunan an-Nasa'i, Volume 1, Book 5, Hadith 463 (DarusSalam) ⓘ

It was narrated from Abu Hurairah that the Messenger of Allah said: "Do you think that is there was a river by the door of any one of you, and he bathed in it five times each day, would there be any trace of dirt left on him?" They said: "No trace of dirt would be left on him." He said: "That is the likeness of the five daily prayers. By means of them Allah erases sins."

أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا اللَّيْثُ، عَنِ ابْنِ الْهَادِ، عَنْ مُحَمَّدِ بْنِ إِبْرَاهِيمَ، عَنْ أَبِي سَلَمَةَ، عَنْ أَبِي هُرَيْرَةَ، أَنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏ "‏ أَرَأَيْتُمْ لَوْ أَنَّ نَهَرًا بِبَابِ أَحَدِكُمْ يَغْتَسِلُ مِنْهُ كُلَّ يَوْمٍ خَمْسَ مَرَّاتٍ هَلْ يَبْقَى مِنْ دَرَنِهِ شَىْءٌ.‏" ‏ قَالُوا لَا يَبْقَى مِنْ دَرَنِهِ شَيْءٌ قَالَ فَكَذَلِكَ مَثَلُ الصَّلَوَاتِ الْخَمْسِ يَمْحُو اللَّهُ بِهِنَّ الْخَطَايَا.