Female workers who uncover their faces on the pretext that it is only the Hanbali school of thought... What is the response?

The questioner:
Honorable Shaykh, may Allah grant you success. The questioner says: I have some female workers of Arab nationality who uncover their faces at work. I advise them to cover their faces, but they refuse, claiming that covering the face is only obligatory according to the Hanbali school of thought, and that they do not follow this school.

The Shaykh:
We ask Allah for safety.

The questioner:
He asks: Am I obligated to...

The Shaykh:
It is not them who obligate you with commands and prohibitions. They have a school of jurisprudence that may coincide with the evidence, or it may err regarding the evidence. But the school of the Muslim is what is established by the evidence. The evidence has been established for the obligation of hijab, whether one is a Hanafi, a Maliki, or a Hanbali. The evidence is an argument for everyone. It is not from our religion that we take it from the schools of jurisprudence; it is taken from the Book and the Sunnah. And the Book and the Sunnah indicate the obligation of hijab for the Muslim woman. Therefore, these women must be informed of this, and they must repent and seek forgiveness from Allah for this statement.