عَنْ عِمْرَانَ بْنِ حُصَيْنٍ رَضِيَ اللَّهُ عَنْهُ قَالَ: كُنْتُ رَجُلًا ذَا أَسْقَامٍ كَثِيرَةٍ فَسَأَلْتُ رَسُولَ اللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَآلِهِ وَسَلَّمَ عَنْ صَلَاتِي قَاعِدًا، قَالَ: ((صَلَاتُكَ قَاعِدًا عَلَى النِّصْفِ مِنْ صَلَاتِكَ قَائِمًا، وَصَلَاةُ الرَّجُلِ مُضْطَجِعًا عَلَى النِّصْفِ مِنْ صَلَاتِهِ قَاعِدًا))
Sayyiduna Imran bin Husain (may Allah be pleased with him) says: I was a man with many illnesses, so I asked the Messenger of Allah (peace and blessings be upon him) about performing prayer while sitting. He (peace and blessings be upon him) said: Your prayer performed sitting is half of that performed standing, and likewise, a man's prayer performed lying down is half of that performed sitting. That is, in terms of reward and merit.