Bulugh al-Maram #326
كتاب الصلاة
وَعَنْ أَبِي هُرَيْرَةَ - رضى الله عنه - قَالَ: "كَانَ رَسُولُ اَللَّهِ - صلى الله عليه وسلم -إِذَا كَبَّرَ لِلصَّلَاةِ سَكَتَ هُنَيَّةً, قَبْلِ أَنْ يَقْرَأَ, فَسَأَلْتُهُ, فَقَالَ: "أَقُولُ: اَللَّهُمَّ بَاعِدْ بَيْنِي وَبَيْنَ خَطَايَايَ كَمَا بَاعَدْتَ بَيْنَ اَلْمَشْرِقِ وَالْمَغْرِبِ, اَللَّهُمَّ نقِّنِي مِنْ خَطَايَايَ كَمَا يُنَقَّى اَلثَّوْبُ اَلْأَبْيَضُ مِنْ اَلدَّنَسِ, اَللَّهُمَّ اِغْسِلْنِي مِنْ خَطَايَايَ بِالْمَاءِ وَالثَّلْجِ وَالْبَرَدِ" مُتَّفَقٌ عَلَيْهِ
Narrated Abu Hurairah (RA) Allah's Messenger (ﷺ) used to keep silent - between the opening Takbir of the prayer and the recitation of the Qur'an - for a short while. Then, I asked him (about that) and he replied, “I say, 'O Allah! Keep me apart from my sins (faults) as you have kept apart the east and west. O Allah clean me from my sins as a white garment is cleaned from dirt. O Allah wash me of my sins with water, snow and hail.”