Sahih Muslim 554
صحيح مسلم#554SahihUqba b. 'Amir al-Juhani reported:Verily the Messenger of Allah (ﷺ) said and then narrated (the hadith) like one (mentioned above) except (this) that he said: He who performed ablution and said: I testify that there is no god but Allah, the One, there is no associate with Him and I testify that Muhammad is His servant and His Messenger
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: 2:21