Sahih Bukhari Volume 007, Book 067, Hadith Number 401.
Narrated By Jabir : We went out in a campaign and the army was called The Army of the Khabt, and Abu 'Ubaida was our commander. We were struck with severe hunger. Then the sea threw a huge dead fish called Al-'Anbar, the like of which had never been seen. We ate of it for half a month, and then Abu 'Ubaida took one of its bones (and made an arch of it) so that a rider could easily pass under it.