Sahih Bukhari Volume 003, Book 044, Hadith Number 663.
Narated By Jabir bin 'Abdullah : "Allah's Apostle sent an army towards the east coast and appointed Abu 'Ubaida bin Al-Jarrah as their chief, and the army consisted of three-hundred men including myself. We marched on till we reached a place where our food was about to finish. Abu- 'Ubaida ordered us to collect all the journey food and it was collected. My (our) journey food was dates. Abu 'Ubaida kept on giving us our daily ration in small amounts from it, till it was exhausted. The share of everyone of us used to be one date only." I said, "How could one date benefit you?" Jabir replied, "We came to know its value when even that too finished." Jabir added, "When we reached the sea-shore, we saw a huge fish which was like a small mountain. The army ate from it for eighteen days. Then Abu 'Ubaida ordered that two of its ribs be fixed and they were fixed in the ground. Then he ordered that a she-camel be ridden and it passed under the two ribs (forming an arch) without touching them."