Surat Al-An'aam (The Cattle) - الأنعام

وَإِن كَانَ كَبُرَ عَلَيْكَ إِعْرَاضُهُمْ فَإِنِ ٱسْتَطَعْتَ أَن تَبْتَغِىَ نَفَقًا فِى ٱلْأَرْضِ أَوْ سُلَّمًا فِى ٱلسَّمَآءِ فَتَأْتِيَهُم بِـَٔايَةٍ وَلَوْ شَآءَ ٱللَّهُ لَجَمَعَهُمْ عَلَى ٱلْهُدَىٰ فَلَا تَكُونَنَّ مِنَ ٱلْجَٰهِلِينَ ﴿٣٥﴾

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.