Translation:

53. That He may make the suggestions thrown in by Satan but a trial for those in whose hearts is a disease and who are hardened of heart: verily the wrongdoers are in a schism far (from the Truth):

Notes (Tafseer)

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 temptation from the satan 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. ii. 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".