According to search-discovered classical Islamic scholarship, the term 'sarāb' (mirage) in Quran 78:20 describes the final, astonishing state of the mountains on the Day of Judgment. Tafsir authorities like Ibn Kathir explain that this is not merely a metaphor; the mountains, the very symbols of terrestrial permanence and stability, will be completely uprooted, pulverized into dust, and scattered by Allah's command. Their transformation will be so absolute that where they once stood, there will be nothing left but an illusion, like a mirage in the desert which appears to be something but is in fact nothing. This event, as analyzed by scholars, is the culmination of a process described across the Quran, including mountains being turned to 'carded wool' (101:5) and 'scattered dust' (56:5-6). The synthesis of these verses reveals a profound theological truth: the seemingly eternal physical world is transient, and its most solid foundations will vanish before the ultimate reality of the Hereafter, demonstrating the absolute power of the Creator.