Surah 36. Yasin, Ayah 66

Lit., "We could surely have effaced their eyes": a metaphor for "We could have created them morally blind" and, thus, devoid of all sense of moral responsibility - which, in its turn, would constitute a negation of all spiritual value in human life as such. (Cf. 2:20 - "if God so willed, He could indeed take away their hearing and their sight".)

In this instance - as, e.g., in 20:96 - the verb basura ("he became seeing" or "he saw") is obviously used in its tropical sense of "perceiving [something] mentally". According to Ibn 'Abbas, as quoted by Tabari, the phrase anna yubsirun signifies "how could they perceive the truth".

"If it had been Our Will": i.e., if such had been the Will and Plan of Allah. If Allah had not intended to give man his limited free-will, or power of choice, the case would have been different: there would have been no moral responsibility which could have been enforced. They could have had no sight or intelligence, and they could not have been blamed for not seeing or understanding. But such is not the case.