Sahih Muslim
The Book of Pilgrimage (Kitab Al-Hajj)
Book Number: 007 / Hadith Number: 2947
Ibn Abbas (Allah be pleased with him) reported that Allah's Messenger (may peace be upon, him) came back from 'Arafa and Usama (Allah be pleased with him) was seated behind him. Usama said that he (the Holy Prophet) continued the journey in this very state until he came to Muzdalifa.