From Sahih Bukhari (Hadith 1116):
Narrated `Abdullah bin Buraida:`Imran bin Husain had piles. Once Abu Ma mar narrated from `Imran bin Husain had said, "I asked the Prophet (ﷺ) about the prayer of a person while sitting. He said, 'It is better for one to pray standing; and whoever prays sitting gets half the reward of that who prays while standing; and whoever prays while Lying gets half the reward of that who prays while sitting
Reference: Bukhari 1116