From Sh. Hassan Kettani:
The advice to [Muslim women who wear niqab] is to stand firm on that and don’t give up, don’t give up!
You are strugglers, you are on the right path, you are on the path of the Prophet’s wives (peace be upon them all). So, stand firm and don’t give up.
Don’t say, “Wwell this is only a Sunnah” or whatever because if everybody says that this Sunnah would disappear and you won’t see it anymore. And then later on, the enemies of Islam would be happy and glad and say, “Okay we have finished the niqab, now then let’s go to the hijab!” And then they will start attacking the hijab and attacking the sisters that are wearing Hijab.
So, now you are in the front line that is defending modesty, defending chastity, and defending the real image of the real Muslim sister.
Later on, you will find that Alhamdulillah Islam has spread. It was rare before and you would find it later [spread] everywhere. SubhanAllah 30 years ago maybe you wouldn’t find any sister wearing hijab in the West, but nowadays Alhamdulillah wherever you go you [can find] hijab and niqab.
These enemies of Islam are trying to fight against hijab and niqab although it’s not something [that has dominated society, because] you [still] find the naked everywhere. But these people are against modesty, against chastity, against all these things because they find that you [sisters] are the lights [in the midst of] the darkness.
They want to attack you like Qawm Lut of Sodom and Gomorrah, when they said kick the people of Lot out of your villages: They are puritans, they purify themselves.
But the answer of his people was only that they said, “Evict them from your city! Indeed, they are men who keep themselves pure.” (Quran 7:82)
Imagine! They want to kick them out of their villages because they purify themselves!
The above is transcribed from Sh Hassan Kettani: