Sahih Muslim 864
صحيح مسلم#864SahihAbu Qilaba reported that he saw Malik b. Huwairith raising his hands at the beginning of prayer and raising his hands before kneeling down, and raising his hands after lifting his head from the state of kneeling, and he narrated that the Messenger of Allah (ﷺ) used to do like this
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: 4:27