What is the ruling on the marriage of a mature, adult woman without the permission of her guardian, and what is the wisdom behind that? Is there a preference for marrying an Arab Muslim over marrying a non-Arab Muslim, even if the non-Arab Muslim is more committed, and what is the wisdom behind that?

A woman is not permitted to marry herself without the permission of her guardian (wali), whether she is mature or immature, adult or not. The wisdom behind this is that the fundamental principle in the rulings of Allah and His Messenger is submission and obedience, as Allah Almighty says: "It is not for a believing man or a believing woman, when Allah and His Messenger have decreed a matter, to have any option in their decision." Some scholars have attempted to deduce the wisdom by stating that a woman possesses strong emotions and may be influenced by the suitor's beauty or wealth. Furthermore, her marriage introduces a stranger into her family, and also, fundamentally, she does not mix with men nor comprehend their circumstances. Therefore, the Lawgiver has appointed a guardian for her to assist and help her.