And if their turning away is hard on you, then if you can seek an opening (to go down) into the earth or a ladder (to ascend up) to heaven so that you should bring them a sign and if Allah had pleased He would certainly have gathered them all on guidance, therefore be not of the ignorant.

And We have made the night and the day two signs, then We have made the sign of the night to pass away and We have made the sign of the day manifest, so that you may seek grace from your Lord, and that you might know the numbering of years and the reckoning; and We have explained everything with distinctness.