Sahih Muslim 285
صحيح مسلم#285SahihIt is narrated on the authority of Abdullah b. Mas'ud that the Prophet observed:He is not one of us (one among the Ummah of Islam) who beat the cheeks or tore the front opening of the shirt or uttered the slogans of (the days of) Jahiliya (ignorance). Ibn Numair and Abu Bakr said (instead of the word" au" (or) it is" wa" [and] the words are) and tore and uttered (the slogans) of Jahiliya without" alif
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih Muslim is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 1:191