Sahih Muslim 1910
صحيح مسلم#1910SahihThis hadith has been narrated by A'mash with the same chain of transmitters in which ('Abdullah b. Mas'ud) said:" I know the manners in which the Messenger of Allah (ﷺ) recited the two surahs in one rak'ah and then twenty surahs in ten rak'ahs
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: 6:338