وَٱلَّذِينَ كَفَرُوا۟ بِـَٔايَٰتِنَا هُمْ أَصْحَٰبُ ٱلْمَشْـَٔمَةِ
Wa'lladhīna kafarū bi-āyātinā hum aṣḥābu'l-mashʾama "And those who disbelieve in Our signs, they are the companions of ill fortune."
- 18: ulāʾika (it is they) + aṣḥābu'l-maymana
- 19: alladhīna kafarū bi-āyātinā (those who disbelieve in Our signs) + hum + aṣḥābu'l-mashʾama
In the eighteenth verse the subject is not described, only pointed to — because its description was already made in the preceding verses (the one who throws himself at the ascent, who believes, who enjoins).
In the nineteenth verse the subject is described anew and openly: "those who disbelieve in Our signs". And the pronoun هُمْ (they) comes in between, which in Arabic conveys restriction (ḥaṣr): it is they precisely.
What this asymmetry does is this: the first group had been defined by a process (climbing the ascent), the second group is defined by an attitude (denial). And the object of the denial is stated: āyātinā — Our signs.
One further observation: for the first group the verb "he believed" was never used on its own — it said "he was of those who believe". For the second group the verb is used directly: kafarū. Denial, that is, is described as an individual act, and faith as a belonging. I record this as my own reading.
Root: ش-ء-م. Shuʾm — ill fortune. Mashʾūm — unlucky. And from the same root shimāl — the left hand, the left side.
Again the two senses together: the left side and ill fortune. Just as in maymana the right and good fortune stood together.
The pattern is again mafʿala — the sixth use in this sūra (together with masghaba, maqraba, matraba, marḥama, maymana, mashʾama). In the last half of the sūra this pattern becomes a rhythm.
This distinction is used in other places in the Qurʾān as well. The plainest parallel is in Sūrat al-Wāqiʿa:
"When you are three kinds: the companions of the right — what of the companions of the right! The companions of the left — what of the companions of the left!" (al-Wāqiʿa 56/7-9)
The same two expressions, in the same structure. The Qurʾān also speaks of the record of deeds being given from the right or from the left/from behind (al-Ḥāqqa 69/19, 25; al-Inshiqāq 84/7, 10).
A bound has to be drawn: this distinction is a symbolism of direction and rests on a relation of fortune and misfortune established within the language itself. From it no ruling can be drawn about the physical right hand or the left hand themselves. What the Qurʾān is using is a distinction ready to hand in the language of the addressee.