17. This shows that even apart from revelation, there is ample evidence in man’s own self, in the structure of the heavens and the earth, and in the order that prevails in the universe to prove that God is the only creator, master, lord and sovereign of the universe. The evidence referred to above also inclines man to believe that the present life will be followed by another one in which man will be required to render an account of his deeds and wherein he might be requited.
18. The “witness from Him” is the Quran. The testimony of the natural phenomena combined with that provided by man’s own self had already created in man the disposition to affirm the truths mentioned earlier. All that was further reinforced by the Quran which came as reassurance that what he was predisposed to believe in was indeed true.
19. In the present context the verse means that those who are overly infatuated with the allurements of a worldly life will be inclined to reject the message of the Quran. Distinguishable from these are those who take full note of the testimony furnished by their own beings and by the structure and order prevailing in the universe in support of God’s unity. This testimony was further reinforced by the heavenly books revealed before the Quran. How could such persons close their eyes to such overwhelming testimony as this and join their voice with those of the unbelievers?
This verse clearly indicates that even before the Quran was revealed, the Prophet (peace be on him) had reached the stage of belief in the Unseen. We have seen, in (Surah Al- Anam Ayat 75), the case of Abraham. Before being appointed as a Prophet, Abraham (peace be on him) was led by a careful observation of the natural phenomena to knowledge of God’s unity. Likewise, the present verse makes it clear that by his reflection, the Prophet (peace be on him), had been led to believe in the Unseen even before the Quran was revealed. Subsequently, when the Quran was revealed it not only confirmed what he had already become inclined to accept, but also provided definite knowledge about it.