Sahih Muslim 4914
صحيح مسلم#4914SahihIt has been reported on the authority of Bara! ' who stated:A man from Banu Nabit (one of the Ansar tribes) came to the Prophet (ﷺ) and said: I testify that there is no god except Allah and that thou art His bondman and Messenger. Then he went forward and fought until he was killed. The Prophet (ﷺ) said: He has done a little but shall be given a great reward
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: 33:209