Sahih Muslim 3598
صحيح مسلم#3598SahihAmra reported that she heard 'A'isha (Allah he pleased with her) discussing fosterage which (makes marriage) unlawful; and she ('A'isha) said:There was revealed in the Holy Qur'an ten clear sucklings, and then five clear (sucklings)
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: 17:31