Thabit bin Ad-Dahhak

Abu Humaid al-Sa'idi, whose full name was Abd al-Rahman ibn Sa'd al-Sa'idi al-Ansari (may Allah be pleased with him), was a Companion of the Prophet ﷺ from the Sa'ida branch of the Khazraj tribe of Medina. He is particularly renowned for a detailed hadith in which he described, before a group of ten Companions who confirmed his accuracy, the precise method of the Prophet's prayer — including how the Prophet ﷺ placed his feet, where he put his hands, how he performed the ruku and sujud, and the way he sat in the tashahhud. This narration, found in the Sunan of Abu Dawud and al-Tirmidhi, is one of the most comprehensive descriptions of the prayer's physical form in the entire hadith literature, and all four legal schools reference it when detailing the recommended acts of prayer. He also narrated hadiths on various aspects of Islamic worship and the Prophet's conduct. His narrations are preserved in the major Sunan collections.