(9) بَابُ: {وَحَرَامٌ عَلَى قَرْيَةٍ أَهْلَكْنَاهَا أَنَّهُمْ لاَ يَرْجِعُونَ}، {أَنَّهُ لَنْ يُؤْمِنَ مِنْ قَوْمِكَ إِلاَّ مَنْ قَدْ آمَنَ}، {وَلاَ يَلِدُوا إِلاَّ فَاجِرًا كَفَّارًا}
Narrated Ibn `Abbas:
I did not see anything so resembling minor sins as what Abu Huraira said from the Prophet, who said, "Allah has written for the son of Adam his inevitable share of adultery whether he is aware of it or not: The adultery of the eye is the looking (at something which is sinful to look at), and the adultery of the tongue is to utter (what it is unlawful to utter), and the innerself wishes and longs for (adultery) and the private parts turn that into reality or refrain from submitting to the temptation."
Reference: Sahih al-Bukhari 6612
In-book reference: Book 82, Hadith 18
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 8, Book 77, Hadith 609