It is narrated from Umm al-Mu'mineen Sayyidah Hafsah (may Allah be pleased with her) that I never saw the Messenger of Allah (peace and blessings be upon him) performing voluntary prayers sitting down, except for one year before his passing; during that time, he (peace be upon him) would perform voluntary prayers sitting and would recite the surah with such excellence and deliberation that it would seem very lengthy.