2/90 — Selling themselves
"How evil is that for which they sold themselves! They rejected what God has sent down, begrudging that God should bestow of His bounty on whichever of His servants He wills."
بِئْسَمَا ٱشْتَرَوْا۟ بِهِۦٓ أَنفُسَهُمْ — the metaphor of trade in the sūra reaches its furthest point here. At verse 16 guidance was sold, at verse 86 the hereafter; here what is sold is the person himself.
بَغْيًا — root b-gh-y: to pass the limit, transgression; and envy. The verse names the cause of the refusal explicitly: "begrudging that God should bestow of His bounty on whichever of His servants He wills."
The objection, then, is not to the content of the revelation but to its recipient. The matter is not "this is not true" but "why was this given to him". It is the same structure as the ground of Iblīs (2/34): there too the matter was not the command itself but whom it favoured. Like pride, envy too is born of a comparison.