Fiqh-us-Sunnah Volume 4, Funerals and Dhikr, Fiqh 4.002A.

Section : A Sick Person is Rewarded for All the Good Deeds that He Would (usually) Perform in a State of Health.

Abu Musa al-Ash’ari reports that the Prophet, peace be upon him, said: “If a servant (of Allah) falls sick or goes on a journey, he (continues to be) rewarded for the good deeds that he used to do when he was healthy or at home.”