If a woman did not cover her feet when praying, out of ignorance, does she have to repeat her prayer?

Praise
be to Allah.

Firstly: 

The scholars (may Allah have mercy on them) differed concerning the ruling
on whether a woman has to cover her feet whilst praying. The majority of
scholars are of the view that it is obligatory for a woman to cover her feet
whilst praying. Shaykh Ibn Baaz (may Allah have mercy on him) was inclined
towards this view. In the answer to question no. 1046 we quoted his words
(may Allah have mercy on him). Please see the question referred to for more
information. 

The other view is that this is not obligatory; this is the view of the
Hanafis and was the view favoured by Shaykh al-Islam Ibn Taymiyah. Ibn
‘Uthaymeen (may Allah have mercy on him) was inclined towards this view. 

It
says in al-Mawsoo‘ah al-Fiqhiyyah (7/86): With regard to the feet,
they are ‘awrah according to the Maalikis and Shaafa‘is, apart from al-Mazani.
This is also the view of the Hanbalis and of some of the Hanafis. 

The most widely-held view among the Hanafis is that the feet are not ‘awrah.
This is also the view of al-Mazani among the Shaafa‘is and of Shaykh Taqiy
ad-Deen ibn Taymiyah among the Hanbalis. End quote.

The majority quoted as evidence for the view that it is obligatory to cover
them the report narrated by Abu Dawood (640) from Umm Salamah (may Allah be
pleased with her), that she asked the Prophet (blessings and peace of Allah
be upon him): Can a woman pray wearing a chemise and headcover and no izaar
(waist-wrapper)? He said: “If the chemise is long enough to cover the tops
of her feet (then that is fine).” 

Al-Khattaabi (may Allah have mercy on him) said: This report supports the
validity of the view of those scholars who did not regard it as permissible
for a woman to pray if any part of her body is uncovered. Do you not see
that he said: “If the chemise is long enough to cover the tops of her feet
(then that is fine).”? Thus he made it a condition of her prayer being valid
that no part of her body should be visible. End quote from Ma‘aalim as-Sunan
(1/159) 

Those who held the second view quoted as evidence the fact that the feet are
part of the woman’s body that is usually visible when she is at home, yet
despite that there is no proven hadith to suggest that it is obligatory to
cover the feet. 

They responded to the hadith of Umm Salamah (may Allah be pleased with her)
by noting that it is mawqoof (i.e., the isnaad does not go back to the
Prophet (blessings and peace of Allah be upon him)). 

Abu Dawood said in his Sunan, after quoting the hadith: This hadith
was narrated by Maalik ibn Anas, Bakr ibn Mudar, Hafs ibn Ghiyaath,
Ismaa‘eel ibn Ja‘far, Ibn Abi Dhi’b and Ibn Ishaaq from Muhammad ibn Zayd,
from his mother, from Umm Salamah, and none of them mentioned the Prophet
(blessings and peace of Allah be upon him). They only attributed it to Umm
Salamah (may Allah be pleased with her). End quote. 

Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said in ash-Sharh al-Mumti‘
(2/161): Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him) was of
the view that the entire body of a free woman is ‘awrah apart from that
which appears of it in her own home, which is the face, hands and feet. He
said: At the time of the Messenger (blessings and peace of Allah be upon
him, women used to wear chemises at home, and not every woman had two
garments. Hence if any menstrual blood got on to her garment, she would wash
it and pray in it, therefore the feet and hands are not ‘awrah in prayer and
are not ‘awrah in the sense that they should be covered in the presence of
non-mahrams. 

As
there is no definitive evidence concerning this matter, I follow the view of
Shaykh al-Islam concerning this issue, and I say that this is what appears
to be the correct view if we do not state that in definitive terms, because
even if a woman has a garment that comes down to the floor, when she
prostrates the soles of her feet will be visible. End quote. 

Secondly: 

If
a woman prayed for some time without covering her feet, and she was unaware
of the ruling, then she does not have to make up those past prayers, because
she is excused due to having been ignorant of the ruling. But she should
make up the prayer that is currently due, if the time for it has not ended. 

Shaykh Muhammad Shams al-Haqq al-‘Azeemabadi (may Allah have mercy on him)
said: Maalik ibn Anas said: If a woman prayed with her hair showing or the
tops of her feet uncovered, she should repeat the prayer if the time for it
has not yet ended.

End quote from ‘Awn al-Ma‘bood Sharh Sunan Abi Dawood (2/242) 

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him) issued two
fatwas, one with the members of the Standing Committee, of which he was the
head (may Allah have mercy on him), and a fatwa of his own that was from the
Fataawa Noor ‘ala ad-Darb collection. Both fatwas say that if the
woman was unaware of the ruling, then she does not have to make up the
prayers. 

It
says in Fataawa al-Lajnah ad-Daa’imah, vol. 2 (5/143): I heard on a
religious show that it is prohibited for a woman to pray with her feet
uncovered; what is the ruling? 

They replied: The woman is required to cover all of her body when praying,
including the feet, which must be covered. As for the face, it should be
left uncovered if there are no non-mahram men nearby. If she offered some
prayers in the past in which her feet were uncovered, then she is pardoned,
in sha Allah, due to having been ignorant of the ruling. And Allah is the
source of strength. End quote. 

Shaykh ‘Abd al-‘Azeez ibn Baaz (may Allah have mercy on him) said: 

With regard to her making up past prayers, that is because she failed to
meet one of the conditions of prayer. If she offered several prayers in
which she did not cover her feet, then she must make them up. But if she was
unaware of the shar‘i ruling, then perhaps Allah, may He be glorified and
exalted, will forgive her for what is past and she does not have to make
them up. It was narrated in a saheeh report from the Prophet (blessings and
peace of Allah be upon him) that when he saw a man praying too quickly, as
if he was pecking the ground, he said to him: “Go back and pray, for you
have not prayed…” [Saheeh – agreed upon]. So the Prophet (blessings and
peace of Allah be upon him) instructed him to repeat that prayer that was
currently due, but he did not instruct him to repeat previous prayers,
because he had been ignorant of the correct manner of praying, although what
appears to be the case is that he had been praying in this manner in the
past, but because he had been ignorant, the Prophet (blessings and peace of
Allah be upon him) excused him for those past occasions but he instructed
him to repeat the prayer that was currently due. This indicates that if
someone is ignorant of one of the obligatory parts of the prayer, then he is
alerted to it before the time for a prayer ends, then he should repeat the
prayer that is currently due, but as for his past prayers, they are still
acceptable, because of his ignorance. This is what is indicated by this
hadith, because the Messenger (blessings and peace of Allah be upon him) did
not instruct this man who prayed badly to repeat all his past prayers,
because of his ignorance and because of the hardship that would be caused by
that. The same applies to the woman who offered many prayers before learning
that it is obligatory to cover the feet; she does not have to repeat them,
in sha Allah, according to the correct view, because she is excused due to
her ignorance. But in the future she must always remember to cover her feet
and the rest of her body, apart from the face and hands, because they are
not ‘awrah when praying, according to the scholars. But if she does cover
her hands, so as to avoid a matter concerning which some of the scholars
differed, that is good.

End quote from Fataawa Noor ‘ala ad-Darb by Ibn Baaz. 

http://www.binbaz.org.sa/mat/14792 

To
sum up: covering the feet when praying, for women, is a matter concerning
which the scholars differed, but to be on the safe side a woman should not
leave her feet uncovered when praying, so as to avoid a matter concerning
which the scholars differed. But with regard to past prayers, she does not
have to make them up, because she is excused for not having been aware of
the ruling. 

And Allah knows best.