Musannaf Ibn Abi Shayba 35:461

Yahya ibn Zakariya ibn Abi Za'idah narrated to us, from Khalid, from Ibn Jurayj, from 'Ata', from Jabir, that the Prophet (peace and blessings of Allah be upon him) said to him: "I have taken your camel for four dinars, and you have its back [the right to ride it] until Medina."