Sahih Muslim
The Book Pertaining to Piety and Softening of Hearts (Kitab Al-Zuhd wa Al-Raqaiq)
Book Number: 042 / Hadith Number: 7091
'A'isha reported that Allah's Messenger (way peace be upon him) died (in such a state) that there had been nothing in my wooden tub which a living being could afford to eat but a handful of barley therein. I had been eating out of that for a fairly long duration when I thought of measuring it and it was almost finished.