Why did Allah command the believing women (al-mu'minat) and not the Muslim women (al-muslimat) in Surat An-Nur and Surat Al-Ahzab to observe hijab, despite the fact that faith (iman) is more specific than Islam?

"Iman" (faith) and "Islam" (submission) are two terms which, when mentioned together, have distinct meanings, but when mentioned separately, they encompass each other. When mentioned together, Iman is more specific than Islam. Iman relates to the heart's تصديق (affirmation/belief), while Islam pertains to the actions of the limbs. However, when Iman is mentioned alone, it encompasses the entire religion, and its command applies to all Muslims. Allah Almighty's address to the believers concerning a matter specific to them aims to convey that the essence of Iman is compliance and prompt execution of the divine command.