«أنا أفصح العرب بيد أني من قريش»
I am the most eloquent of the Arabs, yet I belong to Quraysh.
The structure starts by asserting eloquence and follows *bayd* with an additional feature treated, in this context, as a further distinction related to eloquence. Bayd creates the expectation of qualification or contrast, which is redirected toward praise.
The exception-like connector introduces a further point of distinction; the initial praise is thus reinforced from a second direction.