Thus, the verse contains an indication of the permissibility of wiping over leather socks.

A person whose hand has been amputated washes whatever remains of the obligatory area. If it has been amputated at the joint, he washes the upper end of the upper arm adjacent to it, …

His statement, “A person whose hand has been amputated washes whatever remains of the obligatory area,” refers—may Allah have mercy on him—to one whose hands have been amputated, as indicated by his statement, “he washes the upper end of the upper arm adjacent to it.”

Thus, he washes whatever remains of the obligatory area, but he does not include, in the case of the amputated limb, an amount beyond what is obligatory. For example, if the arm has been amputated halfway along the forearm, he should not wash up onto the upper arm by an amount equal to half the forearm, because the upper arm is not an area to be washed. Rather, he washes whatever remains of the obligatory area, due to the saying of Allah Most High:

“So fear Allah as much as you are able.” [al-Taghabun 16]

This person has feared Allah as much as he is able. It is also due to the Prophet’s saying: “When I command you to do something, do of it as much as you are able.” (1) Whatever has been amputated is no longer subject to the obligation.

His statement, “If it has been amputated at the joint, he washes the upper end of the upper arm adjacent to it,” means: if it has been amputated at the elbow joint, he washes the upper end of the upper arm, because the upper end of the upper arm and the elbow are on the same level.

It has previously been mentioned (2) that the hands must be washed along with the elbows. The upper end of the upper arm is included within the elbow, and so it must be washed. But if the limb is amputated above the joint, washing it is not obligatory.