Sahih Muslim , Book 1, Hadith 230 (USC-MSA) ⓘ
It is narrated on the authority of Abu Huraira that the Messenger of Allah observed: Verily Allah forgave my people the evil promptings which arise within their hearts as long as they did not speak about them or did not act upon them.
حَدَّثَنَا سَعِيدُ بْنُ مَنْصُورٍ، وَقُتَيْبَةُ بْنُ سَعِيدٍ، وَمُحَمَّدُ بْنُ عُبَيْدٍ الْغُبَرِيُّ، - وَاللَّفْظُ لِسَعِيدٍ - قَالُوا حَدَّثَنَا أَبُو عَوَانَةَ، عَنْ قَتَادَةَ، عَنْ زُرَارَةَ بْنِ أَوْفَى، عَنْ أَبِي هُرَيْرَةَ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " إِنَّ اللَّهَ تَجَاوَزَ لأُمَّتِي مَا حَدَّثَتْ بِهِ أَنْفُسَهَا مَا لَمْ يَتَكَلَّمُوا أَوْ يَعْمَلُوا بِهِ " .
also referenced under: Book 1, Hadith 238 (In-Book) & Hadith 127 (Reference)