Sahih Muslim 2512
صحيح مسلم#2512SahihThis hadith has been narrated on the authority of Aswad b. Qais with the same chain of transmitters, but herein no mention has been made of the other month (consisting of) thirty 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: 13:18