Riyad as-Salihin 485
'Abdullah bin Mas'ud (May Allah be pleased with him) reported:
Messenger of Allah (ﷺ) slept on a straw mat and got up with the marks left by it on his body. Ibn Mas'ud (May Allah be pleased with him) said, "O Messenger of Allah! Would that you make us spread out a soft bedding for you." He (ﷺ) replied, "What have I to do with the world? I am like a rider who had sat under a tree for its shade, then went away and left it." [At- Tirmidhi, who classified it as Hadith Hasan Sahih] .
وعن عبد الله بن مسعود، رضي الله عنه، قال‏:‏ نام رسول الله صلى الله عليه وسلم، على حصير، فقال وقد أثر في جنبه‏.‏ قلنا‏:‏ يا رسول الله لو اتخذنا لك وطاء‏!‏ فقال‏:‏ ‏"‏ مالي وللدنيا‏؟‏ ما أنا في الدنيا إلا كراكب استظل تحت شجرة ثم راح وتركها”‏.‏ 
‏(‏‏(‏رواه الترمذي وقال‏:‏ حديث حسن صحيح‏)‏‏)‏‏.‏