Ibne Mas’ood (may Allaah be pleased with him ) narrates that Allaah’s messenger صلى الله عليه وسلم said :
” It is astonishing that a believer is terrified by illness. If he only knew what was in store for him because of illness, he would desire to be ill throughout his life.”
Rasullullah صلى الله عليه وسلم then raised his head towards the heavens and smiled. He was asked :”O Rasullullah ! Why did you look towards the heavens and smile?”
Rasullullah صلى الله عليه وسلم replied : ” I was astonished to see two angels looking for a person at the place where he used to offer salah but they did not find him there.
They returned and said: ‘O our Sustainer! There was such and such servant of Yours whose deeds of the day and night which he used to do, we used to record.
We found that You confined him in Your ropes [i.e. He is unable to move about].’ Allaah replied: ‘ Record for My servant the deeds that he used to do by day and night and do not decrease his reward.
As long as I keep him confined, I take the responsibility for rewarding him. He shall receive the reward of what he used to do [when he was not confined].”