I have seen many sisters who, despite being very particular about covering themselves in public including wearing the Niqab, let their sleeves hang when they drive cars. Islamically, is this allowed? Do I need to make sure that my arm is fully covered when I drive a car?
You have brought up a very important issue, sister, which without doubt needs addressing. As explained in detail in a previous answer titled: ‘A Comprehensive Guide to a Woman’s Nakedness’, a Muslim woman’s nakedness (awra) in the presence of non-Mahram (non-related/marriageable kin) men consists of the whole body except her face, hands and feet.
This is something that is, by and large, agreed upon by the whole Muslim Umma, in that, with the exception of her face, hands and feet, a woman must conceal her body fully with loose and opaque clothing.
Imam al-Marghinani, a renowned Hanafi jurist, states in his Al-Hidaya:
‘It is not permitted for a man to look at the whole body of a non-Mahram woman [due to it being part of Awra] except for her face and hands, for Allah Most High says: ‘Women must not display their beauty and ornaments except what appear thereof.’ (Surah al-Nur: 31). Sayyiduna Ali and Sayyiduna Ibn Abbas (Allah be pleased with them) have both interpreted ‘except what appear thereof’ with the face and hands…’ (Al-Hidaya, 4/458)
Imam al-Tumurtashi (Allah have mercy on him) states in Tanwir al-Absar:
‘A woman’s Awra consists of her whole body except her face, hands and feet. However, she is to be prevented from exposing her face in amongst [non-Mahram] men due to the fear of temptation (fitna).’ (See: Radd al-Muhtar, 1/405. Also see Al-Fiqh al-Islami wa Adillatuh 1/744-754 for references from the Maliki, Shafi’i and Hanbali Schools).
Accordingly, the ‘hand’ represents up to (and including) the wrist only. As such, it is imperative for a woman to ensure that no part from above her wrist is exposed in the presence of non-Mahram men. Muslim sisters driving cars must not be careless in this regard and should avoid wearing loose sleeves that roll up the arms easily. It is undoubtedly possible for others to see the exposed area above the wrist when driving, especially when driving at a slow pace. They must be extra vigilant when driving and wear long tight sleeves, buttoned sleeves, or use a safety pin to hold the sleeves in place.
And Allah knows best
[Mufti] Muhammad ibn Adam
Leicester , UK