وَٱلْيَوْمِ ٱلْمَوْعُودِ
Sentence structure
وَٱلْيَوْمِ is coordinated with the preceding genitive oath noun, and ٱلْمَوْعُودِ is its matching genitive adjective.
Ayah summary
An oath is sworn by the promised Day of Resurrection.
وَٱلْيَوْمِ — And the Day
Grammar: وَ coordinates, ٱل is the definite article, and يَوْمِ is a genitive noun coordinated with the preceding oath noun.
ٱلْمَوْعُودِ — Promised
Grammar: ٱل is the definite article; مَوْعُودِ is a passive participle serving as the genitive adjective of ٱلْيَوْمِ.