And when he knew that the greatest warning is the Day of Judgment, he made the matter terrifying by asking about it, informing that he is worthy of devoting his life to caring about it and asking about the reality of his condition, a question of faith and submission, not a question of disbelief and tyranny. So that he would be more grounded in the warning about it, he said: "And what will make you know?" meaning, it informs you, even if you strive to seek knowledge of it, "What is the Day of Judgment?" meaning, what is it in its length, its terrors, its horrors, and its earthquakes.