When. a slave falls sick, reward will be recorded for him according to what he was doing in the state of health.
(When a slave is sick, he gets reward to his credit according to the deeds he was doing when he was healthy)
46) Narrated Uqba bin Aamir : The Prophet said: Every deed of a day is sealed up. When a believer falls ill, the angels say: 0 our Lord! Your slave so-and-so has fallen ill. The Lord ~J~ says: Note down to his credit the same deeds, he was doing before illness, until he heals up or dies.
(This Haditb is sound and reported by Ahmad in his Musnad).