Abu Bashīr al-Ansāri (may Allah be pleased with him) reported:
He was with the Messenger of Allah (may Allah's peace and blessings be upon him) on one of his journeys, and he sent a messenger ordering: "There should not remain any necklace of string or any other kind of necklace around the necks of camels without being cut."
Reported by Muslim (No. 2115), Al-Bukhari (No. 3005), Abu Dawud (No. 2552), Malik (No. 1713) and Ahmad (No. 20882).
As the Prophet (may Allah's peace and blessings be upon him) was on one of his journeys, and the people were in their sleeping places where they would pass the night in their dwellings and tents, he sent someone to the people ordering them to cut the necklaces hung around the camels' necks, be they made of strings - bowstrings - or any other material, like bells or sandals. This is because they used to hang these necklaces for protection against the evil eye. Hence, they were ordered to cut them, as they are of no avail against the evil eye, and benefit and harm lie in the Hand of Allah alone, with no partner.
Lessons
It is prohibited to hang strings and necklaces to bring about benefits or ward off evils, for this is an act of Shirk (polytheism).
There is nothing wrong with hanging a necklace without a string, as adornment, or for the purpose of riding an animal or tying it.
It is obligatory to show disapproval of wrong things, according to one's ability.
A person's heart should be attached to Allah alone, with no partner.
Explanation in Arabic
كان النبيُّ صلى الله عليه وسلم في بعض أسفاره، والناسُ في مكان نومِهم الذي يَبِيْتُون فيه في رِحالِهم وخيامِهم، فأَرْسَلَ شخصًا إلى الناس يأمرهم بِقَطْع القَلَائد التي تُعَلَّق على البعير سواء كانت من الوَتَر -وَتَر القَوْس- أو من غيره كالجَرَس أو النعل، وذلك لأنهم كانوا يُقَلِّدونها حذرًا من العين، فأُمِرُوا بقطعها؛ لأنها لا تَرُدُّ عنهم شيئًا، وأنَّ النفعَ والضرَّ بيد الله وحده لا شريك له.
تحريم تعليق الأوتار والقلائد لجلب النفع أو دفع الضر؛ لأن ذلك من الشرك.
ربط القلادة من غير الوتر إذا كان للزينة أو لقيادة الدابة أو لربطها به فلا بأس به.