Sunan Ibn Majah, Chapter: The Chapters on Ascetism (Zuhd)

"The Messenger of Allah (saw) sent us, (we were) three hundred men, carrying our provisions on our necks. Our provisions ran out until there would be for (every) man among us one date (a day)." Then it was said: "O Abu Abdullah, how can one date satisfy a man?" He said: "When we no longer had it, we realized how much it was worth. Then we came to the sea and found a whale that had been thrown up by the sea, and we ate from it for eighteen days."