The Book of Pilgrimage (Kitab Al-Hajj)
Muslim :: Book 7 : Hadith 2948
Hisham (Allah be pleased with him) reported from his father: Usama (Allah be pleased with him) was asked in my presence or I asked Usama b. Zaid andhe rode behind Allah's Messenger (may peace be upon him) as he came back from 'Arafat. I said (to him): How did Allah's Messenger (may peace be upon him) journey as he came back from 'Arafat? Thereupon he said: He made it (his riding camel) walk at a slow speed, and when he found an open space, he made it walk briskly.