Concise Quran Commentary
If their denial and turning away from the truth you have brought is difficult for you, O Messenger, then see if you can find a tunnel into the ground or a ladder into the sky so that you may bring them more proof in addition to what I have already given you. If Allah willed to guide them to the guidance that you brought, He would have done so. However, He has not willed this because of His wisdom. So do not be among those who are ignorant of this and lose yourself in regret over their denial.