The Rites of Hajj (Kitab Al-Manasik Wa'l-Hajj)

Dawud :: Book 10 : Hadith 1959

Narrated Az-Zuhri:

Uthman offered complete prayer at Mina for the sake of bedouins who attended (hajj) in large numbers that year. He led the people four rak'ahs in prayer in order to teach them that the prayer (i.e. noon or afternoon prayer) essentially contained four rak'ahs.