A ---It means the inward and outward disbelief such as those disbelievers from among the people of Quraish and the previous nations. Regarding them, Allah the Almighty says: {Those who deny the Book (this Qur'an), and that with which We sent our Messengers (i.e. to worship none but Allah Alone sincerely, and to reject all false deities and to confess resurrection after the death for recompense) they will come to know (when they will be cast into the Fire of Hell)}. (Ghafir,70)

Allah the Almighty says: {And turn away from the foolish (i.e. don't punish them)}. (Al-A' raf, 199)

Allah the Almighty says: {And (remember) the Day when We shall gather out of every nation a troop of those who denied Our Ayat (proofs, evidences, verses, lessons, signs, revelations, etc.), and (then) they (all) shall be set in array (gathered and driven to the place of reckoning). Till, when they come, (before their Lord at the place of reckoning), He will say: "Did you deny My Ayat whereas you comprehended them not by knowledge (of their truth or falsehood), or what (else) was it that you used to do?"}.

(An-Naml, 83, 84)

Allah the Almighty says: {Nay, they have belied the knowledge whereof they could not comprehend and what has not yet been fulfilled (i.e. their punishment). Thus those before them did belie.

Then see what was the end of the Zalimun (polytheists and wrong-doers)!}. (Yunus, 39)