Reference: Fataawa wa Rasaa.il Mukhtaarah – Pages 562-563
Question: What is the ruling regarding a woman wearing tight fitted clothing infront of (other) women and those men who are her mahram?
Response: It is not befitting for the woman to wear tight fitting clothes which make apparent the size of the parts (of her body) in front of her relatives or amongst (other) women, (since) this is contrary to maintaining her chasteness. As for (doing so only) in front of her husband, then there is no harm in that.
So it is obligatory that the dress of the Muslim woman be loose fitting and not tight, so as not to accentuate any part of her body. This is because the aim of the garment is to cover (the body) and (thereby) prevent fitnah; And this is (certainly) not achieved except by (wearing) loose fitting and flowing (clothes).
As for tight fitting (clothes) – even if it hid the colour of the skin, it still accentuates the size of her body or part of it, thereby creating a desirable sight in the eyes of the men; And therein is corruption and an invitation (to evil) which is apparent. So it is obligatory that it be loose fitting.
And it has been narrated by Usaamah ibn Zayd (radhi-yAllaahu ‘anhumaa) who said:
The Messenger of Allaah ﷺ clothed me with a thick white linen garment which had been gifted to him by Dahiyyah al-Kalbee, so I clothed my wife with it, and he said:
«What is the matter with you, you do not wear the thick white linen garment?»
So I said: I have clothed my wife with it, so he said:
«Be sure that she wears a ghilaalah underneath it, for indeed I fear it (the thick white linen garment) accentuating her body and bones», transmitted by ad-Dhiyaa al-Maqdasee in “al-Ahaadeeth al-Mukhtaarah”, and Ahmad, and al-Bayhaqee in “as-Sunan al-Kubraa”, and al-Albaanee declared it hasan in “Jilbaab al-Mar.ah al-Muslimah”.
And a ghilaalah is a fine textured and light shirt-like gown which is worn underneath a garment to prevent accentuating her body.
And with Allaah lies All Success.