Jami` at-Tirmidhi 2770
جامع الترمذي#2770SahihNarrated Jabir bin Samurah:"I saw the Messenger of Allah (ﷺ) reclining upon as pillow, on his left side
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Ahmad Muhammad ShakirSahih
Al-AlbaniSahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 43:40