(2) باب الاِقْتِدَاءِ بِسُنَنِ رَسُولِ اللَّهِ صلى الله عليه وسلم
Narrated Hudhaifa:
Allah's Messenger (ﷺ) said to us, "Honesty descended from the Heavens and settled in the roots of the hearts of men (faithful believers), and then the Qur'an was revealed and the people read the Qur'an, (and learnt it from it) and also learnt it from the Sunna." Both Qur'an and Sunna strengthened their (the faithful believers') honesty. (See Hadith No. 208)
Reference: Sahih al-Bukhari 7276
In-book reference: Book 96, Hadith 9
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 9, Book 92, Hadith 381