كَلَّا ۖ بَلْ ۜ رَانَ عَلَىٰ قُلُوبِهِم مَّا كَانُوا۟ يَكْسِبُونَ
Sentence structure
كَلَّا deters and بَلْ shifts the statement. Relative مَا is the subject of رَانَ; كَانُوا۟ يَكْسِبُونَ is its relative clause, with the returning object omitted after يَكْسِبُونَ.
Ayah summary
Persistent sins have rusted their hearts, so they no longer recognize the truth.
كَلَّا ۖ — Nay
Grammar: A deterrent/refutational particle.
بَلْ ۜ — But
Grammar: A transition/contrast particle resuming the corrected statement.
رَانَ — (the) stain has covered
Grammar: A third-person masculine-singular perfect. Relative مَا is its explicit nominative subject, and عَلَىٰ قُلُوبِهِم is linked to it.
عَلَىٰ — [over]
Grammar: a preposition functioning as the linked complement.
قُلُوبِهِم — their hearts
Grammar: A genitive plural noun governed by عَلَىٰ; attached هِم is its genitive possessor.
مَّا — (for) what
Grammar: A relative pronoun functioning as the nominative subject of رَانَ.
كَانُوا۟ — they used to
Grammar: A deficient masculine-plural perfect. Attached و is the noun of كَانَ and the final alif is orthographic.
يَكْسِبُونَ — earn
Grammar: A masculine-plural imperfect forming the predicate of كَانُوا۟. Attached و is its subject, final ن marks the indicative, and the returning object of relative مَا is omitted.