Maliks Muwatta Book 49, Hadith Number 39.

Section : Pulling off Necklaces and Bells from the Necks of Camels.

Yahya related to me from Malik from Abdullah ibn Abi Bakr from Abbad ibn Tamim that Abu Bashir al-Ansari told him that he was with the Messenger of Allah, may Allah bless him and grant him peace, on one of his journeys. He related, “The Messenger of Allah, may Allah bless him and grant him peace, sent a messenger.” (Abdullah ibn Abi Bakr said, (I think that he said it was while the people were in their resting place.) He said, “Do not let a single-string necklace, or any necklace, remain unbroken on the neck of a camel.”

Yahya said, “I heard Malik say, ‘I think that was because of the evil eye.'”