Sahih Muslim 2894
Sahih Muslim · Book 54: The Book of Tribulations and Portents of the Last Hour · The Hour Will Not Begin Until The Euphrates Uncovers A Mountain Of Gold
Abu Huraira reported Allah's Messenger (ﷺ) as saying:
حَدَّثَنَا سَهْلُ بْنُ عُثْمَانَ ، حَدَّثَنَا عُقْبَةُ بْنُ خَالِدٍ ، عَنْ عُبَيْدِ اللَّهِ ، عَنْ أَبِي الزِّنَادِ ، عَنْ عَبْدِ الرَّحْمَنِ الأَعْرَجِ ، عَنْ أَبِي هُرَيْرَةَ ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم " يُوشِكُ الْفُرَاتُ أَنْ يَحْسِرَ عَنْ جَبَلٍ مِنْ ذَهَبٍ فَمَنْ حَضَرَهُ فَلاَ يَأْخُذْ مِنْهُ شَيْئًا " .
The Euphrates would soon uncover a mountain of gold but he who is present there should not take anything from that.