Amr bin Sa'd (may Allah have mercy on him), the freed slave of Umar bin al-Khattab (may Allah be pleased with him), narrates that Umar bin al-Khattab (may Allah be pleased with him) passed by us on his way back from Hajj, and with him was a group of the Companions of the Messenger of Allah (peace and blessings be upon him). He said: Bathe in the sea, for it is indeed blessed. Then he called for towels, and they dismounted and bathed.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب صلاة الاستسقاء / 6458