Is it considered disbelief for someone who experiences a whisper of doubt (waswasa) regarding a Qur’anic verse to say: "If one of the البشر (human beings) had said what is mentioned in these words, I would not have believed him, but since this is the speech of Allah Almighty and Glorified, I believe Him," and then feel fear concerning his statement while remaining convinced?

Self-talk, whispers of Satan, and thoughts that cross the mind without being acted upon are not held against a person شرعًا (Islamically), as long as the person does not utter them or act upon them. This is based on the saying of the Prophet (peace and blessings be upon him): "Indeed, Allah has forgiven my Ummah for what they self-talk, as long as they do not act upon it or speak of it." The mentioned saying does not cause disbelief. One must beware of dwelling on these whispers, for whoever's Islam is established with certainty, it does not depart except with certainty. The best cure for whispers is to disregard them.