إِذِ ٱنۢبَعَثَ أَشْقَىٰهَا
Sentence structure
إِذِ is a past-time adverb linked to the preceding statement. ٱنۢبَعَثَ is a Form VII perfect, and أَشْقَىٰهَا is its nominative subject with attached هَا as possessor.
Ayah summary
The most wretched among them rose to carry out the deed.
إِذِ — When
Grammar: A past-time adverb linked to the preceding statement and introducing the following clause. This adverbial expression relates to «كَذَّبَتْ».
ٱنۢبَعَثَ — (was) sent forth
Grammar: A Form VII third-person masculine-singular perfect whose explicit subject follows.
أَشْقَىٰهَا — (the) most wicked of them
Grammar: A masculine nominative elative noun functioning as subject; attached هَا is the possessor.