Al-Harith bin Suwaid said:
" 'Abdullah [bin Mas'ud] narrated two Ahadith to us, one of them from himself and the other from the Prophet (s.a.w). 'Abdullah said: 'The believer sees his sins as if he was at the base of a mountain, fearing that it was about to fall upon him. The wicked person sees his sins as if (they are) flies are hitting his nose" he said: "Like this" - motioning with his hand - "to get them to fly away."
English reference: Vol. 4, Book 11, Hadith 2497
Arabic reference: Book 37, Hadith 2685