Narrated `Aisha: Allah's Apostle prayed in his house while sitting during his illness and the people prayed behind him standing and he pointed to them to sit down. When he had finished the prayer, he said, "The Imam is to be followed and so when he bows you should bow; and when he lifts his head you should also do the same."

Narrated Anas bin Malik: Allah's Apostle (p.b.u.h) fell down from a horse and his right side was either injured or scratched, so we went to inquire about his health. The time for the prayer became due and he offered the prayer while sitting and we prayed while standing. He said, "The Imam is to be followed; so if he says Takbir, you should also say Takbir, and if he bows you should also bow; and when he lifts his head you should also do the same and if he says: Sami`a l-lahu liman hamidah (Allah hears whoever sends his praises to Him) you should say: Rabbana walakal-Hamd (O our Lord! All the praises are for You.") (See Hadith No. 656 Vol. 1).

Narrated `Imran bin Husain: (who had piles) I asked Allah's Apostle about the praying of a man while sitting. He said, "If he prays while standing it is better and he who prays while sitting gets half the reward of that who prays standing; and whoever prays while Lying gets half the reward of that who prays while sitting."