كَلَّا لَمَّا يَقْضِ مَآ أَمَرَهُۥ
Sentence structure
لَمَّا negates completion up to now and makes يَقْضِ jussive. Relative مَآ is its object, and أَمَرَهُۥ is the relative clause.
Ayah summary
The human being has not yet fully carried out what his Lord commanded him.
كَلَّا — Nay
Grammar: كَلَّا is a deterrent particle.
لَمَّا — Not
Grammar: لَمَّا is a negative, jussive and past-shifting particle whose negation continues up to the present.
يَقْضِ — he has accomplished
Grammar: A third-person masculine singular imperfect verb, jussive under لَمَّا; its jussive sign is deletion of the final weak yāʾ, and its subject is an implicit هُوَ.
مَآ — what
Grammar: مَآ is a relative pronoun functioning as the object.
أَمَرَهُۥ — He commanded him
Grammar: third-person masculine singular perfect verb; it functions as the relative clause. Attached هُۥ is a third-person masculine singular pronoun functioning as the object.