«وَإِمَّا بِالتَّكْرِيرِ لِنُكْتَةٍ لِيَكُونَ إِطْنَابًا لَا تَطْوِيلًا»
Another form uses repetition for a particular point, so that it becomes iṭnāb rather than mere prolixity.
Repeating wording or an idea may strengthen emphasis, warning, threat, preference or emotional impact. The first occurrence communicates the substance; the second can direct renewed, more forceful attention to it.
If repetition produces no communicative difference at all, added word count alone cannot make the passage rhetorically commendable.