And assuredly We have variously propounded in this Qur'an for mankind every kind of similitude; and man is of all things the most disputing. 54 What prevents people from having faith when guidance comes to them or from asking for forgiveness from their Lord before they face the kind of torment that the ancient people experienced or a new form of torment. 55 And We send not the Envoys, but good tidings to bear, and warning. Yet do the unbelievers dispute with falsehood, that they may rebut thereby the truth. They have taken My signs, and what they are warned of, in mockery. 56 And who could be more wicked than he to whom his Sustainer's messages are conveyed and who thereupon turns away from them, forgetting all [the evil] that his hands may have wrought? Behold, over their hearts have We laid veils which prevent them from grasping the truth, and into their ears, deafness; and though thou call them onto the right path, they will never allow themselves to be guided. 57 Yet, [withal,] thy Sustainer is the Truly-Forgiving One, limitless in His grace. Were He to take them [at once] to task for whatever [wrong] they commit, He would indeed bring about their speedy punishment [then and there]: but nay, they have a time-limit beyond which they shall find no redemption 58 And these towns (population, 'Ad, Thamud, etc.) We destroyed when they did wrong. And We appointed a fixed time for their destruction. 59