2833 If any suggestion comes to the human mind that is not in accordance with Allah's Will and Plan, it has two opposite effects: to evil minds it is a trial and a temptation from the Evil One, but to the mind well-instructed in Faith, it stands self-condemned at once, and becomes a means of strengthening the Faith and stimulating redoubled efforts to conform to the Will of Allah. 2834 Cf.
2:10. I understand the "disease in the heart" to be an earlier state of curse, which leads in an intensified form to a complete "hardening of the heart".