Tafsir of Az-Zumar 39:36-37

{Is Allah not sufficient for His servant?} The interrogative particle of negation (hamzat al-inkār) is prefixed to the word of negation (nafy), thereby establishing and confirming the meaning of sufficiency. It is also recited as "sufficient for His servants" (bi-kāfi ‘ibādihi), referring to the prophets.

The context is that the Quraysh said to the Messenger of Allah (ﷺ): "We fear that our gods will strike you with madness, and we fear for you their harm because you have insulted them." It is also narrated that when he sent Khalid to al-‘Uzza to destroy it, its custodian said to him: "I warn you, O Khalid! It possesses a power that nothing can withstand." Khalid proceeded to it and smashed its nose.

Thereupon, Allah (Mighty and Majestic is He) said: "Is Allah not sufficient for His Prophet to protect him from every evil and repel from him every affliction in times of fear?" This contains mockery of them, for they sought to frighten him with that which possesses no power to benefit or harm.

Alternatively, it may mean: "Is Allah not sufficient for His prophets?" For their nations said similar things to them, yet Allah sufficed them. This is like the statement of the people of Hud: {We say nothing but that some of our gods have possessed you with evil} (Hud: 54).

It is also permissible that it refers to "the servant" and "the servants" in an absolute sense, for He is sufficient for them in hardships and the guarantor of their interests. It is also recited as bi-kāfī ‘ibādihi (genitive construction), and yukāfī ‘ibādahu. Yukāfī may be non-hamzated, a mufā‘ala form derived from kifāya (sufficiency), similar to saying yujāzī (to reward) for yujzā. This is more emphatic than kafā due to its structure denoting hyperbole. It may also be hamzated, from mukāfa’a (requital), in light of the preceding verse: {And He will reward them their due}.

{...by those other than Him?} He means the idols they took as gods besides Him.

{...Mighty} Invincible, unassailable.

{...Possessor of Retribution} He takes retribution from His enemies. In this is a threat to the Quraysh and a promise to the believers that He will take retribution for them against their enemies and grant them victory over them.

{And if you asked them, "Who created the heavens and the earth?" they would surely say, "Allah." Say, "Have you then considered what you invoke besides Allah? If Allah intended me harm, are they removers of His harm? Or if He intended me mercy, are they withholders of His mercy?" Say, "Sufficient for me is Allah; upon Him rely the [wise] relyers."}