وَٱلنَّهَارِ إِذَا تَجَلَّىٰ
Sentence structure
وَٱلنَّهَارِ is coordinated as another genitive oath noun. إِذَا تَجَلَّىٰ is its time clause; تَجَلَّىٰ is a Form V perfect with understood subject.
Ayah summary
And by the day as it becomes bright.
وَٱلنَّهَارِ — And the day
Grammar: وَ coordinates; ٱل defines the masculine genitive oath noun نَّهَارِ. An omitted circumstantial element is associated with «ٱلنَّهَارِ».
إِذَا — when
Grammar: A non-governing temporal adverb introducing the following time clause. This phrase is linked through an omitted element.
تَجَلَّىٰ — it shines
Grammar: A Form V third-person masculine-singular perfect with understood subject هُوَ.