Sahih Bukhari
Saying Something under Compulsion (Ikraah)
Volume: 009 / Book Number: 085 / Hadith Number: 74
Narrated Anas:
Allah's Apostle said, "Whoever possesses the (following) three qualities will have the sweetness of faith (1): The one to whom Allah and His Apostle becomes dearer than anything else; (2) Who loves a person and he loves him only for Allah's Sake; (3) who hates to revert to atheism (disbelief) as he hates to be thrown into the Fire."