Sahih Muslim 1235
صحيح مسلم#1235SahihAbdullah b. Shakhkhir narrated it on the authority of his father that he said prayer with the Messenger of Allah (ﷺ), and he spat and then rubbed it off with his left shoe
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: 5:73