the covering is effected by it; but if it is an outer garment, then the covering is effected by the garment beneath it. Thus, a distinction is made between the two. The apparent meaning of the author’s words, however, is that there is no distinction.
The stronger view is the one mentioned previously: prayer performed in an unlawful garment is valid.
Issue: If someone who has prayed in an unlawful garment asks us about it, he is not to be instructed to repeat the prayer. But if he asks us before praying, we say: You must remove it—not merely for the sake of the prayer, but because it is an unlawful garment whose use is not permissible. There is a difference between allowing a person to use something unlawful—in which case we do not allow him to do so—and his asking about a matter that has already passed and ended, in which case he is not instructed to repeat the prayer. According to the madhhab, however, repetition is obligatory.
For prayer in an unlawful garment to be deemed invalid, it is stipulated that the person be aware and mindful. If he is ignorant or forgetful, he does not have to repeat it.
Issue: If he finds only an unlawful garment, may he pray in it? ...
The answer is that we must consider the matter. If it is unlawful due to the rights of other people, such as a usurped garment, then he must not pray in it. Thus, if he has nothing but a usurped garment, we say: Remove the garment and pray naked. It is not permissible for you to pray in the garment, because it is unlawful due to the rights of other people—unless you are compelled to wear it to ward off the cold; in that case, pray in it, because wearing it then becomes permissible.
But if it is unlawful due to the right of Allah, there is no harm in praying in it. For example, if a man has only a silk garment, he prays in it, because a prohibition connected to the right of Allah is lifted in cases of necessity. He should then pray in it and does not have to repeat the prayer. Likewise, if his garment contains images, he may pray in it if he finds no other garment.