Towards the end of his life, Hazrat Moulana Ahmad Shah Saahib (rahmatullahi ‘alaih) suffered some type of a sickness affecting his bladder. He passed urine by using a tube attached to a bottle, which he held in his hands. He even had to travel in this condition.
Someone once asked him: “What is the cause of this sickness?”
“My evil actions,” he lamented.
Puzzled, the man asked: “What evil actions are you talking about?”
“For years on end, I was able to pass urine a few times in a day with ease and comfort. However, not once did this ungrateful tongue of mine ever express gratitude to Allah Ta‘ala for this favour of His. Which action can be more evil than this? Allah Ta‘ala has warned us of His punishment for ingratitude:
وَلَئِن كَفَرْتُمْ إِنَّ عَذَابِي لَشَدِيدٌ
“And if you are ungrateful, indeed My punishment is severe.” (Surah Ebrahim, v7)
(Discourses of Faqeeh-ul-Ummah Hazrat Mufti Mahmood Hasan Gangohi, vol. 2, pg. 5)