It has been reported from ʿUthmān ibn ʿAffān (may Allah be pleased with him):
“No one ever conceals an inner intention without Allah bringing it to light upon the surfaces of his face and the slips of his tongue.”

We have already elaborated on this point in the discussion of faith, showing that whatever lodges in the heart—assent, love of Allah and His Messenger, and reverence—must necessarily manifest itself through the limbs, and the converse is equally true. Thus, the absence of an outward, necessary concomitant is proof of the absence of the corresponding inward reality. This accords with the sound hadith of the Prophet (Allah bless him and grant him peace):
“Truly, within the body there is a morsel of flesh; if it …”