Shaykh ul-Islaam Ibn Taymeeyah [رحمه الله] said:
«لا يحصل المرض إلا لنقص أسباب الصحة كذلك القلب لا يمرض إلا لنقص إيمانه.»
❝Sickness does not occur except due to a deficiency in reasons of health, likewise the heart does not become sick except due to deficiency of its Eemaan.❞
[Majmoo Al-Fatawa, (10/637) | Translated By Abbas Abu Yahya Miraath Al-Anbiyya]