The Book of Prayers (Kitab Al-Salat)

Muslim :: Book 4 : Hadith 1597

Hafsa reported: Never did I see the Messenger of Allah (may peace be upon him) observing supererogatory prayer sitting till one year before his death when he would observe Nafl prayer in a sitting position, and he would recite the Surah (of the Qur'an) in such a slow-measured tone (that duration of its recital) became more lengthy than the one longer than this.

Source materials are from the University of Southern California MSA site
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