Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrates: Once it was mentioned before me that some people, after bathing in the sea of Khidr, say: It is obligatory upon us to bathe again with other water. (Sayyiduna Ibn Abbas, may Allah be pleased with them both, said:) "Whoever is not purified by the water of the sea, may Allah not purify him."
Hadith Referenceسنن الدارقطني / كتاب الطهارة / 79
Hadith Takhrij«أخرجه الدارقطني فى ((سننه)) برقم: 78»