Sahih Muslim 1565
صحيح مسلم#1565SahihAbu Qatada reported that when the Messenger of Allah (ﷺ) was in a journey he got down for rest at night, and he used to lie down on his right side, and when he lay down for rest before the dawn, he used to stretch his forearm and place his head over his palm
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: 5:398