You are asking first about the niqab: is it obligatory or a recommended practice, and what is the evidence from the Qur'an and the Sunnah?

Question:
You are asking first about the niqab: is it obligatory or a recommended practice? And what is the evidence from the Qur'an and the Sunnah? Because there has been a difference of opinion among us regarding this topic, please inform us. May Allah reward you with good.

Answer:
Yes, covering the face is obligatory from men who are not among the woman's mahram (relatives one may not marry), and this...
...depends on the custom of the country. If it is their custom to wear the niqab, which does not cover the face, and only the eyes are visible from it, then she wears the niqab. And if she is from the desert and it is their custom to wear the burqu', which is also similar to the niqab, covering the face except for the eyes, then she wears the burqu'. But if it is their custom to wear the full covering and cover the face entirely, as is the case with the custom of many city dwellers, then it is obligatory for her to cover her face with what is customary to cover it with. Yes. May Allah reward you with good, and may He do you good.