«جزى بنوه أبا الغيلان»
His sons recompensed Abū al-Ghaylān.
Jazā: a past-tense verb, “recompensed.”
Banūhu: a nominative subject; banū is in annexation and hāʾ is the possessive pronoun referring to a later noun.
Abā al-Ghaylān: an accusative direct object and the antecedent intended by that pronoun.
The issue: the pronoun within the subject refers back to the object, which appears later both in wording and syntactic rank. Saying only “the pronoun came first” would miss the crucial role of grammatical rank.