Advice of Scholars - AWRAT PARTS
Those parts of a responsible person’s body which are harâm for him (or her) to open and show others and for others to look at while performing namâz, or any time, are called Awrat parts. Men and women were commanded to cover their awrat parts through the sûras of Ahzâb and Nûr, which were revealed in the third year of the Hegira. In Hanafî and Shâfi’î Madhhabs a man’s awrat parts for namâz are between his navel and lower parts of his knees. The knees are awrat in Hanafî and the navel is awrat in Shâfi’î. The namâz performed with these parts open is not acceptable. When performing the namâz, it is sunnat for men to cover their other parts [arms, head], [and to wear socks if a long robe or a gown is not available]. It is mekrûh for them to perform the namâz with these parts exposed.
All parts of free women, except their palms and faces, including their wrists, outer parts of their hands, hanging parts of their hair and under their feet are awrat for namâz, in Hanafî. There are also valuable books saying that outer parts of hands are not awrat. According to them, it is permissible for women to perform namâz while outer parts of their hands up to wrists are bare. But, for having followed all the books, it is better for women to perform namâz wearing a gown with sleeves long enough, or a head cover large enough, to cover their hands. There are (savants) who said that women’s feet were not awrat in namâz, but those same savants said that it was sunnat to cover and mekrûh to open them when performing namâz and when going out. [It is written in the book Kâdihân that hanging parts of hair are like feet]. If one-fourth of a man’s or woman’s awrat part remains bare as long as one rukn, the namâz becomes annulled. If a smaller part remains exposed, the namâz does not become nullified, but it becomes mekrûh. For instance, the namâz of a woman one-fourth of whose foot has remained bare will not be sahîh. If she herself uncovers it, her namâz becomes annulled immediately.