إِيَّاكَ نَعْبُدُ
You alone we worship.
The object pronoun «إِيَّاكَ» is fronted before the verb. Its special placement conveys exclusivity: worship is directed to Allah alone. Pronoun choice and word order can work together for a rhetorical effect.
A pronoun is not automatically clear. A third-person reference such as “he” needs a recoverable antecedent or context. Concision is eloquent only when it does not leave the hearer uncertain about the referent.