Ruling on preventing women with improper hijab from entering the mosque
Question

                Is it permissible to prohibit women who are
      not covered in the proper islaamic covering from entering the masjid ? (after they have
      been given the proper naseeha) Please advise the daleel.Jazzakallahu khayrun
Praise be to Allah.Alone, and peace and blessings be
    upon him after whom there is no Prophet.
    If a woman comes to the mosque wearing improper hijab, then according
    to Islam she should be advised and have explained to her – with the daleel or proof
    – the fact that hijab is obligatory, and the seriousness of neglecting it. If she
    then complies, then praise be to Allah. If she does not comply, then do not let her enter,
    because of the fitnah (temptation) and evil involved in her actions. The Prophet 
 (peace
    and blessings of Allaah be upon him) said: “Any woman who has put on bukhoor
    (incense, fragrance) should not attend this ‘Isha’ prayer with us.” (Reported
    by Muslim, 675). And he 
 (peace and blessings of Allaah be upon him) said
    concerning women’s going out to the mosque: “Let them go out unperfumed” (reported
    by Abu Dawood, 478), i.e., not wearing any perfume. Women have to go out
    wearing complete Islamic hijab, and not wearing adornment or perfume. And Allaah knows
    best.