(4) باب فَضْلِ الْوُضُوءِ وَالصَّلاَةِ عَقِبَهُ
Humran, the freed slave of Uthman reported:
One day Uthman b. Affan performed the ablution well, and then said: I saw Allah's Messenger (ﷺ) perform ablution, the best ablution, and then observed: He who performed ablution like this and then went towards the mosque and nothing (but the love of) prayer urged him (to do so), all his previous (minor) sins would be expiated.
Reference: Sahih Muslim 232a
In-book reference: Book 2, Hadith 15
USC-MSA web (English) reference(deprecated numbering scheme): Book 2, Hadith 446