Sahih Bukhari Volume 4, Book 52, Hadith Number 226.

Narated By Wahb bin Kaisan : Jabir bin ‘Abdullah said, “We set out, and we were three-hundred men carrying our journey-food on our shoulders. Then we began to eat a single date each per day.” A man asked (Jabir), “O Abu ‘Abdullah! How could a person be satisfied with a single date?” Jabir replied, “We realized the value of that one date when we could not even have that much till we reached the sea-shore, when all of a sudden we saw a huge fish cast by the sea. So, we ate of it as much as we wished for eighteen days.”