Tafsir of Al-Mulk 67:13

{And conceal your speech or publicize it}: This is a general address to those who are morally obligated (mukallafin), as in His saying: {so that He may test you}. This is connected to an implied phrase. It is stated in al-Kashf that the original structure of the speech is: "And for those among you, O those who are obligated and tested, who disbelieve, and for those among you who fear [Him]."

This second part [the verse mentioning those who fear] serves as an answer to a question that drips from the exposition regarding the state of the disbelievers—namely: "What is the state of those who do the best in deeds, and those who emerge refined upon being tested?" Thus, the answer was given by His saying, {Indeed, those who fear [their Lord] unseen...}, thereby affirming for them the perfection of knowledge—{Only those among His servants fear Allah who have knowledge}—and the perfection of piety, because of His saying, {unseen}. In this interruption, there is a reinforcement of the meaning alluded to in His saying, {who of you is best in deed}, meaning: "so that He may test you as to who among you is the one of piety," specifically identifying them as the ones intended. If it had been connected by a conjunction, it would have indicated equality. Then it is said: "So fear Him in secret and in public, and persist, O you who fear, in your fear, and return to fear and piety, O you who are deluded, and believe that your secrets and your public declarations are equal in the knowledge of your Lord; therefore, be cautious and fear Him with the true fear." Thus, His saying {that} is connected to this implied element.

It is permissible to consider His saying, {Indeed, those who...}, as a digression following the mention of the disbelievers and their recompense. His saying, {And conceal... or publicize it}, is by way of a shift in address (iltifat) toward the companions of the Blaze, due to the distance of the context and for greater specificity, being connected to His saying, {And for those who disbelieve in their Lord is the punishment of Hell}. It is as if it were said: "And for those who disbelieve in their Lord is the punishment of Hell," and then their characteristics were mentioned as being such-and-such. "And your concealment of speech or your publicizing of it, O you disbelievers, is the same; you will not escape Us. Whether you publicize disbelief and hatred or keep it hidden, it is all the same." This is part of the completion of the threat. Then He said, "The first [view] is more acceptable."

It appears to me that the first view is more distant, and the second is supported by what has been narrated from Ibn Abbas, who said: "{And conceal your speech...} was revealed regarding the polytheists, who used to speak ill of the Prophet (may Allah bless him and grant him peace), and so revelation would come to him (peace and blessings be upon him). Some of them would say to others, 'Conceal your speech so that the Lord of Muhammad does not hear.' Thus, it was said to them: 'Conceal that or publicize it, for Allah the Exalted knows it.'" The precedence of "secret" over "public" is to signal their exposure and the occurrence of what they fear from the very beginning, and to emphasize the comprehensiveness of His knowledge (Exalted be He) which encompasses all information—as if His knowledge (Exalted be He) of what they conceal is prior to His knowledge of what they publicize, despite the fact that both are, in reality, equal. Or it is because the stage of the secret precedes the stage of the public; for there is nothing that one publicizes except that it, or its foundations, is usually concealed in the heart. Thus, His knowledge (Exalted be He) of its first state precedes His knowledge of its second state.

{Indeed, He is Knowing of that which is within the breasts}: This is an explanation for what precedes it and a confirmation thereof. In the form of the fa'il (intensive form), the adornment of "breasts" with the article of totality (the alif-lam of encompassing), and describing the innermost thoughts as "possessors of breasts" (dhat al-sudur), there is a profundity that is not hidden. It is as if it were said: "Indeed, He (Exalted be He) is intensive in encompassing the hidden things of all people and their secrets that are concealed and lodged within their chests, to the extent that they almost never depart from them at all; so how could He not know what you conceal and what you publicize?" It is also permissible that "that which is within the breasts" refers to the hearts that are in the breasts, meaning that He (Exalted be He) is knowing of the hearts and their states, so no secret of their secrets is hidden from Him.