—if the hadith is sound—the prayer of one who lets his garment hang below his ankles is invalid, because he has worn a prohibited garment. Thus, if the prayer is invalidated by wearing a prohibited garment, then wiping is likewise invalidated by wearing prohibited leather socks.

Covering the required area, …

His statement, “covering the required area,” means the part of the foot that is obligatory to wash. This is the fourth condition: for wiping over the leather socks to be permissible, they must cover the required area.

What is meant by “covering” is that no part of the required area may be visible through them, whether because they are transparent, thin, or have holes in them.

For if they have holes, the required area becomes visible through them, and wiping over them is not valid. Some scholars—even according to the well-known position of the madhhab—said that this applies even if the hole is only the size of the head of an awl.

The reasoning is that when something is thin or has holes, whatever is exposed must be washed; and washing cannot be combined with wiping, since the two cannot come together on a single limb.

As for something through which the skin is visible due to its transparency, this is because covering is a condition, and such a thing is not covering. The proof is that if a person were to pray in a garment through which the skin is visible because of its transparency, his prayer would be invalid.

The Shafi'is hold that it is permissible to wipe over something that does not cover due to its transparency (1), because the place that must be washed is covered and water cannot reach it. The fact that the skin can be seen through it does not matter, for this is not an awrah that must be covered