The Prophet ﷺ was asked about the water of the sea. He said, "Its water is purifying, and its dead creatures are lawful to eat."
أن النبي ﷺ سئل عن ماء البحر، فقال: هو الطهور ماؤه، الحل ميتته.
Narrated by Ibn Majah (388), who said, Muhammad bin Yahya told us, Ahmad bin Hanbal told us, Abu Qasim bin Abu Zinad told us, who said, Ishaq bin Hazim told me, from Ubaydullah - who is Ibn Muqsim - from Jabir, and he related the hadith. Its chain of transmission is hasan, on account of Abu Qasim bin Abu Zinad, for there is nothing objectionable about him, and Ishaq bin Hazim is truthful.Hafiz Abu Ali bin Sakan said, "The hadith of Jabir is the most sahih of what has been narrated on this subject," and he included it among the sahih narrations in his Sunan. See Tuhfat al-Muhtaj (1/136, no. 3) and Talkhis (1/1).The hadith is found in Musnad Imam Ahmad (3/373), and through this same route it was also narrated by Ibn Khuzayma (112) and Ibn Hibban (1244). Hakim also narrated it (1/143) as a corroborating witness for the hadith of Abu Hurairah.On this subject there is also a report from Ali bin Abu Talib, narrated by Daraqutni (1/35) and Hakim (1/142), and Hakim remained silent about it. Hafiz said in Talkhis (1/12), "It comes through the route of the family of the Prophet, and its chain contains someone unknown."There is also a report from Anas bin Malik, narrated by Abdul-Razzaq (320) and Daraqutni (1/35), from Thawri, from Aban bin Abu Ayyash, from Anas. Daraqutni said, "Aban is discarded as a narrator."There is also a report from Ibn Abbas, narrated by Daraqutni and Hakim, and Daraqutni graded its stopped version (mawquf) as sahih.There is also a report from Abdullah bin Amr, narrated by Daraqutni and Hakim by way of Amr bin Shuayb, from his father, from his grandfather, and Hakim remained silent about it. This comes through the route of Muthanna, from Amr bin Shuayb. Hafiz said, "Muthanna is daif."There is also a hadith from Abu Bakr Siddiq, narrated by Daraqutni, and in its chain is Abdul-Aziz bin Imran, who is Ibn Abu Thabit. Dhahabi said, "There is consensus on his weakness." There is another route for it, but it is stopped (mawquf).There is also a hadith from Ibn Firasi, narrated by Ibn Majah. Tirmidhi said, "I asked Muhammad about it, and he said, 'This is a disconnected (mursal) report, for Ibn Firasi did not meet the Prophet ﷺ, though Firasi himself was a companion.'"Hafiz said, "On this basis, it seems either that the words 'from his father' have been dropped from the narration, or that the word 'Ibn' is an addition, for Imam Bukhari mentioned that Muslim bin Makhshi did not meet Firasi himself, but rather narrates from his son, and that the son was not a companion. Bayhaqi narrated it through the route of the teacher of Ibn Majah's teacher, Yahya bin Bukayr, from Layth, from Jafar bin Rabia, from Muslim bin Makhshi, that he was told that Firasi said, 'I was hunting...' This wording is well constructed, though according to Bukhari's view it is still mursal." For more, see Nasb Raya (1/99).As for the hadith of Ibn Masud concerning wudu with nabidh (date-soaked water), it is not sahih. This is what was narrated by Abu Dawud (84), Tirmidhi (88), and Ibn Majah (384), that the Prophet ﷺ said to him on the night of the jinn, "What is in your water-skin?" He said, "Nabidh." He said, "A good date and pure water." Its chain revolves around Abu Zayd, from Ibn Masud, and he is a man unknown to the scholars of hadith, with no known narration besides this one, as Tirmidhi stated. Bukhari said, "Abu Zayd, who narrated the hadith of Ibn Masud, is an unknown man, not known to have been a companion of Abdullah." Ibn Abdul-Barr said, "Abu Zayd, the freed slave of Amr bin Hurayth, is unknown to them, not recognized, and his report from Ibn Masud concerning wudu with nabidh is a rejected (munkar) report with no basis, not narrated by anyone reliable, and not established."I say, Muslim narrated with his chain from Ibn Masud, who said, "I was not with the Messenger of Allah on the night of the jinn, and I wish I had been with him."It is also reported from Ibn Abbas that the Messenger of Allah said, "Nabidh serves as wudu for one who cannot find water," and this is a rejected (munkar) hadith. It was narrated by Daraqutni (1/75) and Bayhaqi (1/12) from the report of Musayab bin Wadih, Mubashir bin Ismail told us, from Uzai, from Yahya bin Abu Kathir, from Ikrima, from Ibn Abbas, and he related it. Bayhaqi said, "This is a hadith disputed with regard to Musayab bin Wadih, and he erred in it in two places, in mentioning Ibn Abbas, and in mentioning the Prophet, for what is preserved is that it is a saying of Ikrima, not raised to the Prophet (marfu)."