Muḥammad 47:8

Wa'lladhīna kafarū fa-taʿsan lahum wa aḍalla aʿmālahum

"And as for those who deny: a fall on the face for them! [God] has made their deeds go astray."

Root: ت-ع-س. The concrete sense the lexicographers record is this: to fall on one's face, to stumble and go headlong. Taʿisa'r-rajul — the man stumbled and fell on his face. As its opposite they record إِنْتِعَاش (to straighten up and rise).

The word is also used as a pattern of imprecation: taʿsan lak — "may your face come to the ground".

And now look at the preceding verse.

Two verses in succession give the two ends of the same physical picture.

This is an opposition standing in the text, and it is invisible unless the concrete senses of the words are known. Set "He makes your feet firm" beside "may they perish" and no link appears; but set "the foot holds on the ground" beside "to go headlong on the face" and the link comes out of itself.

And this is a good example of what root analysis is for: the concrete sense of words makes the link between verses visible.

تَعْسًا is in the accusative and has no verb. The grammarians count it an absolute object; the implied form: atʿasahumu'llāhu taʿsan — "may God make them fall on their faces".

That is, the verb has been dropped and the verbal noun has remained — just like the fa-ḍarba'r-riqāb of the fourth verse. The sūra uses this construction twice.

And in Arabic this construction is the standard form of sentences of imprecation and prayer: saqyan lahu, tabban lahu. Indeed the opening of Sūrat al-Masad (tabbat yadā Abī Lahab) was treated in al-Masad; the construction there and this verse are of the same family.

This clause is the last two words of the first verse of the sūra. Letter for letter.

The only difference is a wāw placed at its head.

This repetition turns the first eight verses of the sūra into a ring:

Eight verses, opening with the same sentence and closing with the same sentence. And in between there is a regulation of war. That is, the regulation has been placed between the descriptions of the two groups.

I record this framing as an observation about word order.