Hadith: Whoever hangs an amulet, may Allah not fulfill his wishes, and whoever hangs a seashell, may Allah not grant him serenity

عن عقبة بن عامر رضي الله عنه مرفوعاً: "من تَعَلَّقَ تَمِيمَةً فلا أَتَمَّ الله له، ومن تَعَلَّقَ وَدَعَةً فلا وَدَعَ الله له" وفي رواية: "من تَعَلَّقَ تَمِيمَةً فقد أَشْرَكَ".
[الأول: ضعيف. الثاني: صحيح] - [رواهما أحمد]

‘Uqbah ibn ‘Āmir (may Allah be pleased with him) reported that the Prophet (may Allah's peace and blessings be upon him) said: "Whoever hangs an amulet, may Allah not fulfill his wishes, and whoever hangs a seashell, may Allah not grant him serenity." Another narration reads: "Whoever hangs an amulet has committed polytheism."
Sahih/Authentic. - [Ahmad]

Explanation

This Hadīth proves that the one who uses amulets out of belief that they can ward off harm is included in those against whom the Prophet (may Allah's peace and blessings be upon him) supplicated that Allah does the contrary of what they intended, and not fulfill their wishes. Also, the Prophet (may Allah's peace and blessings be upon him) supplicated against those who use seashells with the same previous intention; he supplicated that Allah does not grant them serenity and peace of mind, and that He, instead, stirs against them everything that may harm them. This supplication is intended to warn people against such deeds. The Prophet (may Allah's peace and blessings be upon him) also informs us in the second Hadīth that this act is considered polytheism.