The prayer of the one who sits is equivalent to half of the Prayer of one who stands Sunan Ibn Majah 1231
Arabic hadith text
حَدَّثَنَا بِشْرُ بْنُ هِلاَلٍ الصَّوَّافُ، حَدَّثَنَا يَزِيدُ بْنُ زُرَيْعٍ، عَنْ حُسَيْنٍ الْمُعَلِّمِ، عَنْ عَبْدِ اللَّهِ بْنِ بُرَيْدَةَ، عَنْ عِمْرَانَ بْنِ حُصَيْنٍ، أَنَّهُ سَأَلَ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ عَنِ الرَّجُلِ يُصَلِّي قَاعِدًا قَالَ " مَنْ صَلَّى قَائِمًا فَهُوَ أَفْضَلُ. وَمَنْ صَلَّى قَاعِدًا فَلَهُ نِصْفُ أَجْرِ الْقَائِمِ. وَمَنْ صَلَّى نَائِمًا فَلَهُ نِصْفُ أَجْرِ الْقَاعِدِ "
Translation
It wasnarrated from ‘Imran bin Husain that he asked the Messenger ofAllah (ﷺ) about a man who prays sitting down. He said, “Whoeverperforms prayer standing up, that is better. Whoever performs prayersitting down will have half the reward of one who prays standing. Andwhoever performs prayer lying down will have half the reward of onewho prays sitting.”