al-Ḥashr 59:4

Dhālika bi-annahum shāqqullāha wa rasūlah, wa man yushāqqillāha fa-innallāha shadīdu'l-ʿiqāb

"This is because they stood in a separate rank against God and His Messenger. And whoever stands in a separate rank against God — surely God is severe in requital."

Root: ش-ق-ق. The original sense of the root is to split, to divide in two, to crack.

This root has occurred in several places in this commentary:

• In the section on al-Ṭāriq 86/12, as one of the three roots that describe the splitting of the soil: falq, ṣadʿ, shaqq.
• "Then We split the earth in a splitting" (ʿAbasa 80/26).
• Sūrat al-Inshiqāq — the splitting of the sky: idha'l-samāʾu'nshaqqat.

Now let us look at the mufāʿala form: شَاقَّ.

Shiqq is one of the two pieces that appear when a thing is split — a "half", a "side". That is, mushāqqa means "you in one piece, I in the other".

This is the root's own description of opposition, and it gives an extremely concrete image: there was a whole; one party split it in two and put himself into the other half.

And now a link with the preceding sūra needs to be made.

Throughout Sūrat al-Mujādala the root ح-د-د was used for the same phenomenon: muḥādda — to draw a boundary, to declare a frontier on the opposite side.

In al-Ḥashr ش-ق-ق is used for the same phenomenon: mushāqqa — to split the whole and cross over to the other piece.

Two neighbouring sūras give the same idea with two different concrete images. The one brings the boundary line to the fore, the other the whole that is split.

And the use of the root on three scales makes an interesting table:

The same verb, on three scales. The splitting of the soil is fertility; the splitting of the sky is the resurrection; the splitting of the ranks is recorded as a crime.

The second half of the sentence turns the event into an instance of a rule: "whoever … ".

And a detail: while the first sentence says "against God and His Messenger", the second says only "against God". The classical exegetes explain this thus: to stand against the Messenger is already to stand against God; in the second sentence the ruling is referred back to its origin.

شَدِيدُ ٱلْعِقَابِ — Root: ع-ق-ب. ʿAqib: the back of a thing, its end; the heel (ʿaqib). ʿIqāb: the requital that comes after an act.

That is, ʿiqāb is not an arbitrary punishment; it is the thing that comes on the heels of the act. The word sets up a bond of time and of causality between the punishment and the act. From the same root ʿāqiba (the end, the place arrived at) and taʿqīb (to follow, to go after).

This will return in the seventeenth verse of the sūra: فَكَانَ عَٰقِبَتَهُمَآ — "and the end of the two of them was this".