Some verses first present a general description and then deny a particular aspect. «وَلَا فَضْلَ فِيهَا»
And there is no excellence in it.
If the denial blocks a likely misconception, it may be useful. If it simply repeats what has already been adequately conveyed without adding specification, its excess can be criticized.
The same form of negation can therefore function as clarification, emphasis, or idle surplus depending on the earlier statement and audience.