Standing for those with the ability to do so is one of the pillars of the obligatory prayers. As for the supererogatory prayers, standing is not one of its pillars. It is permissible for the Muslim to perform the supererogatory prayer while sitting, however a person will have a reward commensurate with his hardship [one is enduring when doing so]. Whoever performs any voluntary prayers sitting [while] capable of standing, will have less reward [for doing so] than for the one who prays standing - like what is expounded on in this hadeeth, [when] ʿImraanibn Husayn(may Allah be pleased with him) asked the Prophet ﷺ about the prayer of a man who performs the sunnahand supererogatory prayers while sitting, [but] can stand. The Prophet ﷺ explained to him that whoever prays standing is better; because standing is more demanding - thus it is greater in reward, and that whoever prays while sitting, his reward is half of that of the one who stands in prayer. Whoever prays while laying down - meaning being situated on their side on the ground [or other surface] - then their reward is half of that of the one who prays while sitting. This ruling is applicable to the one who is able to perform the prayer while standing, but still choose to pray sitting down or by laying on his side. In this case, he will decrease his reward by doing so. As for the one incapable of standing, it suffices him to sit or lay on their side [while praying] - and their reward is complete [with no decrease]. From the other benefits that we can conclude from this hadeeth is noting the easiness that the Islamic Law makes for Muslims in their acts of worship, and the preference of standing over sitting when performing any supererogatory prayers; and [likewise] the preference of sitting over laying down - if one is capable of doing so. .