Tafsir of Al-A'raf 7:12

{ألا تسجد} The lā (لا) in an lā tasjud (أن لا تسجد) is an expletive (redundant/emphatic), as evidenced by His saying: "What prevented you from prostrating (an tasjud) to that which I created with My hands?" (Ṣād: 75). Similar to this is: "So that the People of the Scripture may know (li-allā yaʿlama)" (al-Ḥadīd: 29), meaning li-yaʿlama (so that they may know).

If you ask: What is the benefit of its addition? I say: It is to emphasize and confirm the meaning of the verb it precedes, as if it were said: "So that the knowledge of the People of the Scripture may be confirmed." And: "What prevented you from confirming the prostration and binding yourself to it?"

{إذ أمرتك} Because My command to you to prostrate made it obligatory upon you—a necessary and inevitable obligation.

If you ask: Why did He ask him about what prevented him from prostrating when He already knew what prevented him? I say: It is for the sake of rebuke, and to manifest his obstinacy, disbelief, arrogance, pride in his own origin, and his contempt for the origin of Adam. It shows that he disobeyed the command of his Lord, believing it was not binding upon him, as he viewed the prostration of the superior to the inferior as being outside the bounds of what is correct.

If you ask: How can his saying, "I am better than him," be an answer to "What prevented you?", when the answer should have been "Such-and-such prevented me"? I say: He initiated a narrative in which he informed [God] of his superiority over Adam and the reason for his superiority—which is that his origin is fire and Adam’s origin is clay. Thus, the answer was understood from it, along with an addition: the rejection of the command and the deeming it unlikely that one like him would be commanded to prostrate to one like him. It is as if he is saying: "Whoever is of this quality, it is inconceivable that he should be commanded to do what he was commanded to do."

{قال فاهبط منها فما يكون لك أن تتكبر فيها فاخرج إنك من الصاغرين}