The Messenger of Allah ﷺ said, "The prayer of one who prays sitting is half the reward of one who prays standing."
حدثنا أبو سعيد حدثنا عبد الله بن جعفر يعني المخزومي وحدثنا إسماعيل بن محمد
أن رسول الله ﷺ قال صلاة القاعد نصف صلاة القائم
Its isnad is sahih. In the printed edition, "Abdullah bin Jafar Makhzumi" appears, which is an error. Ismail bin Muhammad is Ibn Saad bin Abu Waqqas, and the hadith has already appeared at 13169.