It was narrated from ‘Uqbah ibn ‘Aamir al-Juhani that a group came to the Messenger of Allaah (peace and blessings of Allaah be upon him) [to swear their allegiance (bay’ah) to him]. He accepted the bay’ah of nine of them but not of one of them. They said, “O Messenger of Allaah, you accepted the bay’ah of nine but not of this one.”
He said,
“He is wearing an amulet.”
The man put his hand (in his shirt) and took it off,
then he (the Prophet (peace and blessings of Allaah be upon him)) accepted his bay’ah. He said, ‘
Whoever wears an amulet has committed shirk.”
(Narrated by Ahmad, 16969)
This hadeeth was classed as saheeh by Shaykh al-Albaani in al-Silsilah al-Saheehah, 492.
https://www.islamawareness.net/BlackMagic/fatwa_amulets.html
