وَالْعُيُونَ بِالْحَوَرِ، وَالْحَوَاجِبَ بِالْبَلَجِ، وَالْمَبَاسِمَ بِالْفَلَجِ
And eyes with the striking contrast of their white and dark, brows with clear separation, and smiles with graceful spaces between the teeth.
Al-ḥawar / al-balaj / al-falaj are near-rhyming terms in a highly stylised oath. The description moves from the eyes to the space between the eyebrows and the appearance of the teeth, accumulating physical details.
A formal oath unexpectedly becomes an ornamental catalogue of beauty. The sound continuity holds the catalogue together; the conceptual effect is to prolong attention to appearance. That aesthetic performance must be separated from proof regarding the accusation under dispute.