Sahih al-Bukhari, Volume 3, Book 28, Hadith 46 (USC-MSA) ⓘ
Narrated Abu Huraira: The Prophet said, "Whoever performs Hajj to this Ka`ba and does not approach his wife for sexual relations nor commit sins (while performing Hajj), he will come out as sinless as a newborn child, (just delivered by his mother).
حَدَّثَنَا مُحَمَّدُ بْنُ يُوسُفَ، حَدَّثَنَا سُفْيَانُ، عَنْ مَنْصُورٍ، عَنْ أَبِي حَازِمٍ، عَنْ أَبِي هُرَيْرَةَ ـ رضى الله عنه ـ قَالَ قَالَ النَّبِيُّ صلى الله عليه وسلم " مَنْ حَجَّ هَذَا الْبَيْتَ، فَلَمْ يَرْفُثْ، وَلَمْ يَفْسُقْ، رَجَعَ كَيَوْمِ وَلَدَتْهُ أُمُّهُ " .
also referenced under: Book 27, Hadith 15 (In-Book) & Hadith 1820 (DarusSalam)