Tafsir of Al-Anfal 8:37

(That Allah may distinguish the wicked from the good) meaning: the disbeliever from the believer, or corruption from righteousness. The particle of causation (lam) in both interpretations is related to "they will be gathered" (yuhsharun).

It may also be intended by "the wicked" that which the polytheists spent for the enmity of the Messenger of Allah, may Allah bless him and grant him peace, and by "the good" that which the Muslims spent for his victory, peace and blessings be upon him. In this case, the particle is related to "it will be a source of regret for them" (takunu 'alayhim hasrah), rather than "they will be gathered," as there is no meaning in providing the reason for their gathering as the distinguishing of wicked wealth from good wealth. Furthermore, it does not relate to "it will be a source of regret" in the first two interpretations, as there is no meaning in providing the reason for their wealth being a source of regret as the distinguishing of disbelievers from believers or corruption from righteousness.

Hamza, al-Kisa'i, and Ya'qub read li-yumayyiza (to distinguish) from tamyiz, which is more emphatic than mayz due to the additional letters in its form. From the former comes: mayyaztuhu fa-tamayyaza; and from the latter comes: miztuhu fa-inmaza. It was read as an anomalous reading: fa-inmazu al-yawma ayyuha al-mujrimun (So separate yourselves today, O criminals).

(And He puts the wicked some of it upon others, so He heaps them all up together) meaning: He joins some of it to others and gathers it, from the expression: "heaped up clouds" (sahab markum). Sand and armies are also described with this. If "the wicked" refers to the disbeliever, the meaning is the extreme crowding of them in the gathering. If it refers to corruption, the meaning is that He, the Exalted, gathers every category of it to the other.

(And He puts it into Hell) all of it. Placing corruption into Hell is by placing its practitioners into it. As for the wealth spent in the enmity of the Messenger, may Allah bless him and grant him peace, placing it into Hell is for their foreheads and sides to be cauterized by it.

It may be intended here to encompass both the disbeliever and that wealth, in the sense that He joins the wicked wealth to the wicked disbeliever to increase his torment thereby, adding the regret of the Hereafter to the regret of the world.

(Those are the losers) This is a reference to the wicked. The plural is used because it is conceptualized as the wicked group, or it refers to the spenders who remained in disbelief, in which case the plurality is manifest. The sense of remoteness contained therein, in both interpretations, is to signify the distance of their rank in wickedness.

(They are the losers) meaning: they are perfect in their loss, for they have lost their own selves and their wealth.