Sahih Muslim 1371
صحيح مسلم#1371SahihAbu Huraira reported the Messenger of Allah (ﷺ) as saying:He who finds a rak'ah of the prayer, he in fact finds the prayer
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: 5:205