The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wa'l-Adab)
Muslim :: Book 32 : Hadith 6276
'Imran b. Husain reported: We were with Allah's Messenger (may peace be upon him) in some of his journeys and there was a woman from the Ansar riding a she-camel that it shied and she invoked curse upon that. Allah's Messenger (may peace be upon him) heard it and said: Unload that and set it free for it is accursed. 'Imran said: I still perceive that (dromedary) walking amongst people and none taking any notice of that.