“The Messenger of Allah (ﷺ) said: ‘The water of the sea is a means of purification and its dead meat is permissible.’”
Sunan Ibn Majah Book 28, Hadith 47
← Previous Hadith “I said: ‘O Messenger of Allah, I have come to you to ask you about the vermin of the earth. What do you say about mastigures?’ He said: ‘I do not eat them and I do not forbid them.’ I said: ‘I will eat of that which you have not forbidden. But why (do you not eat them), O Messenger of Allah?’ He said: ‘One of the nations was turned into beasts and I looked at this creature and was uncertain.’ I said: ‘O Messenger of Allah, what do you say about rabbits?’ He said: ‘I do not eat them and I do not forbid them.’ I said: ‘I will eat of that which you have not forbidden. But why (do you not eat them), O Messenger of Allah?’ He said: ‘I have been told that it menstruates.’”

Sunan Ibn Majah Book 28, Hadith 46 Next Hadith → “Whatever the sea throws out or is left behind when the tide ebbs, eat it, but whatever rises to its surface, do not eat it.’”

Sunan Ibn Majah Book 28, Hadith 48