Sahih Muslim 5120
صحيح مسلم#5120SahihUmm Salama reported Allah's Apostle (ﷺ) as saying:If anyone of you intends to offer sacrifice he should not get his hair cut or nails trimmed
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: 35:54