Is it permissible for decent women to reveal their faces and hands only?
It is impermissible for a Muslim woman to reveal her face except for her Mahrams (spouse or unmarriageable relatives), as Allah (Exalted be He) says:
...and to draw their veils all over Juyûbihinna (i.e. their bodies, faces, necks and bosoms) and not to reveal their adornment except to their husbands, or their fathers, or their husband’s fathers, or their sons, or their husband’s sons
The face is the main place of adornment.
related on the authority of
`Aishah (may Allah be pleased with her) who said:
"May Allah be merciful with the first emigrant women; when the Ayah (Qur'anic verse) which states:
...and to draw their veils all over Juyûbihinna (i.e. their bodies, faces, necks and bosoms)
was revealed, they tore their thick outer garments and made veils for themselves."
(Part No. 17; Page No. 152) May Allah grant us success. May peace and blessings be upon our Prophet Muhammad, his family, and Companions.