Bhashya
न्यार्थता वास्तु; न त्वेव ब्रह्मैकत्वप्रतिपत्त्यर्थता ॥
In plain words
Let's grant it serves some other purpose, then. But that's not it at all — the only reason is to bring you to see that Brahman is one.
Close to the Sanskrit
—for another purpose, let it be so; but that is not at all [the case] — rather, [it is] for the sake of the realization of the oneness of Brahman.