Mustadrak al-Hakim — Hadith 8854

It is narrated from Sayyiduna Hudhayfah (may Allah be pleased with him) that he went out to the outskirts of Kufah, and a man was with him. He looked towards the Euphrates and said to his companion: "What will be your state when you see them coming out, or being driven out, from there, and they will not taste even a single drop of its (the Euphrates') water?" A man asked: O Abu Abdullah! Is that what you think? He said: "It is not what I think; rather, I know it (with certainty)."
This hadith is sahih (authentic) on the condition of the two Shaykhs (Bukhari and Muslim), but they did not record it.