Wills and Testaments (Wasaayaa)

Bukhari :: Book 4 :: Volume 51 :: Hadith 17

Narrated Anas:

The Prophet saw a man driving a Badana (i.e. camel for sacrifice) and said to him, "Ride on it." The man said, "O Allah's Apostle! It is a Bandana." (The Prophet repeated his order) and on the third or fourth time he said, "Ride it, (woe to you" or said: "May Allah be merciful to you)."