Sahih Bukhari Volume 2, Book 26, Hadith Number 763.

Narated By ‘Ikrima : Abu Huraira said, “The Prophet saw a man driving a Badana (sacrificial camel). The Prophet (p.b.u.h) said (to him), ‘Ride on it.’ He replied, ‘It is a Badana.’ The Prophet again said, ‘Ride on it!’ Abu Huraira added, ‘Then I saw that man riding it, showing obedience to the Prophet (p.b.u.h), and a shoe was (hanging) from its neck.'”