The Messenger of Allah ﷺ said, "When the Muslim, or believing, servant performs ablution and washes his face, every sin he looked at with his eyes leaves his face with the water, or with the last drop of water, or something like that. When he washes his hands, every sin his hands committed leaves them with the water, or with the last drop of water, until he emerges cleansed of sins."
حدثنا إسحق بن موسى الأنصاري حدثنا معن بن عيسى القزاز حدثنا مالك بن أنس ح و حدثنا قتيبة عن مالك عن سهيل بن أبي صالح عن أبيه
قال رسول الله ﷺ إذا توضأ العبد المسلم أو المؤمن فغسل وجهه خرجت من وجهه كل خطيئة نظر إليها بعينيه مع الماء أو مع آخر قطر الماء أو نحو هذا وإذا غسل يديه خرجت من يديه كل خطيئة بطشتها يداه مع الماء أو مع آخر قطر الماء حتى يخرج نقيا من الذنوب
Sources. Muslim also narrated it in the book of Purification, in the chapter on sins departing with the water of wudu, hadith 244, from the hadith of Malik through the same chain, and it is found in Muwatta (Yahya), 1/32.On this topic there are also narrations from Uthman bin Affan [Bukhari, hadith 159, and Muslim, hadith 226], Thawban [referring to the hadith in Ibn Majah, hadith 277], and Sanabihi [Ibn Majah, hadith 282, and others], as well as Amr bin Abasa [Muslim, hadith 832, at length], Salman [Shuab al-Iman by Bayhaqi, 3/15, hadith 2737, which has a corroborating witness in Ahmad, 5/437–439], and Abdullah bin Amr [perhaps referring to the hadith of Ibn... etc, sahih, narrated by Ibn Majah, hadith 278].There is also the hadith, "Indeed I will boast about your numbers before the other nations" [hadith 3944], which Busiri graded sahih.