The Messenger of Allah ﷺ came out upon some people who were praying while seated due to illness, and he said, "The prayer of one who sits is half the prayer of one who stands."
حدثنا عبد الملك بن عمرو حدثنا عبد الله بن جعفر عن إسماعيل بن محمد
خرج رسول الله ﷺ على ناس وهم يصلون قعودا من مرض فقال إن صلاة القاعد على النصف من صلاة القائم
Its isnad is sahih. Abdullah bin Jafar bin Abdul-Rahman bin Miswar bin Makhrama is well-regarded by them, and his hadith appears in Muslim. Ismail bin Muhammad bin Saad bin Abu Waqqas is trustworthy and reliable. This hadith has already appeared at 12335.