إِرَمَ ذَاتِ ٱلْعِمَادِ
Sentence structure
إِرَمَ identifies the preceding Aad. ذَاتِ describes Iram and is annexed to ٱلْعِمَادِ, which is genitive.
Ayah summary
They were the people of ‘Ad of Iram, possessors of lofty pillars.
إِرَمَ — Iram
Grammar: A proper noun identifying the preceding Aad; it is diptote and therefore bears fatḥah in its genitive/appositional position.
ذَاتِ — possessors (of)
Grammar: A feminine genitive adjective of إِرَمَ, annexed to the following noun.
ٱلْعِمَادِ — lofty pillars
Grammar: ٱل is the definite article; عِمَادِ is the genitive complement of ذَاتِ.