He used to describe to us the prayer of the Messenger of Allah ﷺ, then he would stand and pray. When he raised his head from the bowing, we would think he had forgotten, from how long he stood.
حدثنا محمد بن جعفر حدثنا شعبة عن ثابت قال سمعت
كان ينعت لنا صلاة رسول الله ﷺ ثم يقوم فيصلي فإذا رفع رأسه من الركوع قلنا قد نسي من طول ما يقوم
Its isnad is sahih. It is found in Bukhari, 2/301, no. 821, and Muslim, 1/344, no. 172.