He entered upon the Messenger of Allah ﷺ in the upper chamber where he had secluded himself from his wives during the time he had taken an oath to stay away from them. The Prophet ﷺ was lying on a reed mat with nothing between him and the mat. Beneath his head was a leather pillow stuffed with palm fibers, near his feet was a pile of tanning leaves, and by his head hung some animal hides. I saw the marks of the mat pressed into the side of the Messenger of Allah ﷺ, and I wept.He asked, "What makes you weep?"I said, "Messenger of Allah, Khosrow and Caesar live in such luxury, while you are the Messenger of Allah ﷺ."He replied, "Are you not pleased that they should have this world and we should have the Hereafter?"
أنه دخل على رسول الله ﷺ في المشربة التي كان قد اعتزل فيها نساءه حين آلى منهن، قال: وإنه لعلى حصير ما بينه وبينه شيء، وتحت رأسه وسادة من أدم، حشوها ليف، وإن عند رجليه قرظا مصبوبا، وعند رأسه أهب معلقة، فرأيت أثرالحصير في جنب رسول الله ﷺ، فبكيت، فقال: ما يبكيك؟ فقلت: يارسول الله إن كسرى وقيصر فيما هما فيه، وأنت رسول الله ﷺ، فقال: أما ترضى أن تكون لهم في الدنيا ولنا في الآخرة؟
Bukhari narrated it in the tafsir (4913), and Muslim in divorce (31:1479), both through Sulayman bin Bilal, who said, Yahya told me, Ubayd bin Hunayn told me, that he heard Abdullah bin Abbas narrating, from Umar bin Khattab, and he mentioned it in a lengthy hadith.