Sahih Bukhari Volume 2, Book 26, Hadith Number 607.

Narated By Nafi  : ‘Abdullah bin ‘Umar’ said, “Allah’s Apostle made his camel sit (i.e. he dismounted) at Al-Batha’ in Dhul-Hulaifa and offered the prayer.” ‘Abdullah bin ‘Umar used to do the same.