The Messenger of Allah ﷺ said, "The Hour will not come until wealth becomes abundant and overflows, so that a man will go out with the zakat of his wealth and find no one to accept it from him, and until the land of the Arabs returns to being meadows and rivers."
أن رسول الله ﷺ قال: لا تقوم الساعة حتى يكثر المال ويفيض، حتى يخرج الرجل بزكاة ماله فلا يجد أحدا يقبلها منه، وحتى تعود أرض العرب مروجا وأنهارا.
Muslim narrated it in the Book of Zakat (157: 60), from Qutayba bin Saeed, from Yaqub (that is, Ibn Abdul-Rahman al-Qari), from Suhayl, from his father, from Abu Hurairah, who mentioned it.His statement, "The land of Arabia will turn back into meadows and rivers." This means that it once had rivers and forests, and humans and animals lived there, and then drought struck it. It has now been established among earth scientists that the Arabian Peninsula once contained fifteen (15) large lakes, around which various groups of humans and animals lived. Drought then struck it about three hundred thousand years before the present time, and excavations at these lakes have revealed a large presence of animals, including elephants, various kinds of gazelles, the Arabian oryx, cattle, camels, buffalo, tigers, hyenas, foxes, horses, hippopotamuses, crocodiles, some birds, and other various animals. This was reported by Professor Abdul-Aziz al-Omari, head of the Saudi team, and Dr. Michael Petraglia, head of the international team and professor of archaeology at the Max Planck Institute for Science in Germany. This is evidence of the truthfulness of the prophethood of Muhammad ﷺ, and the land of Arabia will indeed turn back from desert into meadows and rivers before the Day of Resurrection, just as the Prophet ﷺ foretold.