Sahih Muslim 6534
صحيح مسلم#6534SahihAbdullah b. 'Umar reported Allah's Messenger (ﷺ) as saying:It is not permissible for a Muslim to have estranged relations with his brother beyond three days
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: 45:33