Sahih Muslim Book 021, Hadith Number 4757.
Chapter : It is permissible to eat the animals of water even if they are dead.
Jabir b. 'Abdullah reported: Allah's Messenger (may peace he upon him) sent us (on an expedition). We were three hundred riders and our chief (leader) was 'Ubaida b. al-Jarrah. We were on the look out for a caravan of the Quraish. So we stayed on the coast for half a month, and were so much afflicted by extreme hunger that we (were obliged) to eat leaves. That is why it was called the Detachment of the Leaves. The ocean cast out for us an animal which was called al-'Anbar (whale). We ate of that for half of the month and rubbed its fat on our (bodies) until our bodies became stout. Abu 'Ubaida caught hold of one of its ribs and fixed that up. He then cast a glance at the tallest man of the army and the highest of the camels and then made him ride over that, and that passed beneath it (the rib), and many a man could sit in its eye-socket, and we extracted many pitchers of fat from the cavity of its eye. We had small bags containing dates with us (before finding the whale). 'Ubaida gave every person amongst us a handful of dates (and when the provision ran short), he then gave each one of us one date. And when that (stock) was exhausted, we felt its loss.