Chapter 1: The Book of Purification
It was narrated that 'Aishah said: "The Prophet (ﷺ) used to say: 'Allahumaghsil khatayaya bi-ma' ith-thalj wal-barad was naqqi qalbi min al-khataya kama naqayta ath-thawb al-abyad min ad-danas (O Allah, was away my sins with the water of snow and hail, and cleanse my heart of sin as a white garment is cleansed of filth.'"
Sunan an-Nasa'i 61