From Sahih Bukhari (Hadith 1819):
Narrated Abu Huraira:Allah's Messenger (ﷺ) said, "Whoever performs Hajj to this House (Ka`ba) and does not approach his wife for sexual relations nor commits sins (while performing Hajj), he will come out as sinless as a newlyborn child. (Just delivered by his mother)
Reference: Bukhari 1819