Sahih Muslim Book 41, Hadith Number 6922.

Chapter : The last hour will not come until the Euphrates uncovers a treasure of Gold.

‘Abdullah b. Harith b. Naufal reported: I was standing along with Ubayy b. Kab and he said: The opinions of the people differ in regard to the achievement of worldly ends. I said: Yes, of course. Thereupon he said: I heard Allah’s Messenger (may peace be upon him) as saying: The Euphrates would soon uncover a mountain of gold and when the people would bear of it they would flock towards it but the people who would possess that (treasure) (would say): If we allow these persons to take out of it they would take away the whole of it. So they would fight and ninety-nine out of one hundred would be killed. Abu Kamil in his narration said: I and Abu Ka’b stood under the shade of the battlement of Hassan.