لَا تُهْمِلِ الْمَوْعِدَ؛ لَا تُهْمِلْهُ.
Do not neglect the appointment; do not neglect it.
The second prohibition may function as purposeful repetition if it reinforces an urgent warning or responds to the addressee’s habitual neglect. If the repetition is contextually pointless, increasing the word count does not itself constitute a rhetorical benefit.
The analysis first identifies exactly what is repeated, then states the effect produced by repetition. Without the latter step, the presence of extra words demonstrates length, not successful amplification.