Tafsir of Muhammad 47:3

{That} is a subject (mubtada’), and what follows it is its predicate (khabar). That is: that matter—which is the rendering of the deeds of one of the two groups as vain and the expiation of the sins of the second—exists because the former followed falsehood and the latter followed the truth.

It is also permissible for {That} to be the predicate of an omitted subject, meaning: the matter is as mentioned, due to this cause. In this case, the position of the prepositional phrase (al-jar wa-l-majrur) is accusative (mansub), whereas in the first case, it is nominative (marfu’).

{Falsehood} is that which is of no benefit. Mujahid said: "Falsehood is Satan." Rhetoricians call this type of discourse "interpretation."

{That} is like that type [of parable] in: {God sets forth for the people their parables}. The pronoun refers to the people, or to the two groups mentioned, meaning: He sets forth their parables for the sake of the people so that they may take heed from them.

If you ask: "Where is the setting forth of parables?" I say: It is in making the following of falsehood a parable for the deeds of the disbelievers, and the following of the truth a parable for the deeds of the believers. Or, it is in making the rendering of deeds as vain a parable for the failure of the disbelievers, and the expiation of sins a parable for the success of the believers.

{So when you meet those who disbelieve, strike their necks until, when you have thoroughly defeated them, bind them firmly. Then either favor [them] afterwards or ransom [them] until the war lays down its burdens. That [is the command]. And if God had willed, He could have taken vengeance upon them, but [He does so] to test some of you by others. And those who are killed in the way of God—never will He waste their deeds. He will guide them and amend their state, and admit them into Paradise, which He has made known to them.}