Praise be to Allaah.
Covering the ‘awrah is a condition of prayer being valid. If
a person plays with his ‘awrah uncovered when he is able to cover it, his
prayer is not valid.
Reciting al-Faatihah is one of the pillars or essential parts
of the prayer without which the prayer is not valid.
For more information please see the answer to questions no.
If a person fails to fulfil one of the conditions of prayer
being valid, such as covering the ‘awrah, or he fails to fulfil one of the
pillars or essential parts of the prayer, such as reciting al-Faatihah, due
to ignorance of the ruling and not intending to go against it, then there is
no sin on him and he does not have to make up past prayers. It was narrated
from Abu Hurayrah (may Allah be pleased with him) that the Prophet
(blessings and peace of Allah be upon him) entered the mosque and a man came
in and prayed, then he came and greeted the Prophet (blessings and peace of
Allah be upon him). The Prophet (blessings and peace of Allah be upon him)
returned the greeting and said: “Go back and pray, for you have not
Narrated by al-Bukhaari, 793; Muslim, 397
Shaykh al-Islam Ibn Taymiyah (may Allah have mercy on him)
He did not instruct him to repeat the prayers he had offered
before that time, even though the man said: By the One Who sent you with the
truth, I cannot do better than that. Rather he instructed him to repeat that
particular prayer because there was still time left for it, and he was
enjoined to offer the prayer during its time. With regard to prayers for
which the time had already passed, he did not instruct him to repeat them
even though he had omitted some of their obligatory parts, because he did
not know that that was obligatory upon him. Similarly, he did not instruct
‘Umar ibn al-Khattaab (may Allah be pleased with him) to make up prayers
that he had not offered because he had been in a state of janaabah, because
he [‘Umar] had not known that it is permissible to offer prayer with
tayammum (dry ablution, in situations where water is not available). And
when the woman who was suffering from istihaadah (ongoing non-menstrual
vaginal bleeding) said to him: I bleed a great deal all the time. What do
you think – should I stop praying and fasting? He told her to do wudoo’ for
each prayer, but he did not instruct her to make up the prayers that she had
End quote from Majmoo‘ al-Fataawa, 21/430
And Allah knows best.