Abdullah bin Amr bin As reported,

I was told that the Messenger of Allah ﷺ said, "A man's prayer while seated is half of the prayer."So I went to him and found him praying while seated. I placed my hand on my head, and he asked, "What is the matter, Abdullah bin Amr?"I replied, "Messenger of Allah, I was told that you said, 'A man's prayer while seated is half of the prayer,' yet you are praying while seated."He said, "That is true, but I am not like any one of you."

Azami 2759

Sahih

عن عبد الله بن عمرو قال

حدثت أن رسول الله ﷺ قال: صلاة الرجل قاعدا نصف الصلاة قال: فأتيته فوجدته يصلي جالسا، فوضعت يدي على رأسي فقال: ما لك يا عبد الله بن عمرو؟ قلت: حدثت يا رسول الله أنك قلت: صلاة الرجل قاعدا على نصف الصلاة وأنت تصلي قاعدا. قال: أجل، ولكني لست كأحد منكم.

الأعظمي 2759صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Prayer
Chapter
Minor actions do not invalidate the prayer
Section
Reward of praying sitting being half that of praying standing
Numbering
Jami al-Kamil 2759 (2nd edition)
Azami 2759