Sunan an-Nasa'i, Volume 1, Book 2, Hadith 334 (DarusSalam) ⓘ

It was narrated that 'Aishah said: "The Prophet used to say: 'Allahummaghsil khatayaya bi-ma'ith-thalj wal-barad was naqqi qalbi min al-khataya kama naqayta ath-thawb al-abyad min ad-danas (O Allah, wash away my sins with the water of snow and hail, and cleanse my heart of snow and hail, and cleanse my heart of sin as a white garment is cleansed of filth).'"

أَخْبَرَنَا إِسْحَاقُ بْنُ إِبْرَاهِيمَ، قَالَ أَنْبَأَنَا جَرِيرٌ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، قَالَتْ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يَقُولُ ‏ "‏ اللَّهُمَّ اغْسِلْ خَطَايَاىَ بِمَاءِ الثَّلْجِ وَالْبَرَدِ وَنَقِّ قَلْبِي مِنَ الْخَطَايَا كَمَا نَقَّيْتَ الثَّوْبَ الأَبْيَضَ مِنَ الدَّنَسِ ‏" ‏ ‏.‏