ٱلَّذِى خَلَقَ فَسَوَّىٰ
Sentence structure
ٱلَّذِى describes the preceding Lord; خَلَقَ is its relative clause. فَسَوَّىٰ is coordinated with the first verb; both verbs have an understood subject and an omitted object.
Ayah summary
Allah created everything and fashioned it perfectly according to wisdom.
ٱلَّذِى — The One Who
Grammar: A masculine-singular relative noun, read here as a genitive adjective explaining the preceding رَبِّكَ; its following clause is the relative clause.
خَلَقَ — created
Grammar: A third-person masculine-singular perfect with understood subject هُوَ. Its object is omitted.
فَسَوَّىٰ — then proportioned
Grammar: فَ coordinates; سَوَّىٰ is a third-person masculine-singular Form II perfect with understood subject هُوَ and omitted object.