Sahih Muslim 2083
صحيح مسلم#2083SahihAnas (b. Malik) reported:It rained upon us as we were with the Messenger of Allah (ﷺ). The Messenger of Allah (way peace be upon him) removed his cloth (from a part of his body) till the rain fell on it. We said: Messenger of Allah, why did you do this? He said: It is because it (the rainfall) has just come from the Exalted Lord
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: 9:14