the Prophet ﷺ said: “The one most versed in the Book of Allah should lead the people in prayer.” (1) Yet he cannot recite. Nevertheless, as far as validity is concerned, the correct view is that his imamate is valid.

Nor may one who is unable to bow, prostrate, sit, or stand …

His statement, “Nor one unable to bow or prostrate,” means that the imamate of one unable to bow is not valid. For example, if a person has back pain and is unable to bow, he may not lead as imam one who is able to bow.

As for one who is unable to bow, it is valid for him to lead another who is likewise unable, since they share the same excuse.

The reasoning is that one able to bow is in a more complete state than one unable to do so, and one who is unable may not lead one who is able. This is the view adopted by the author, and it is the position of the madhhab.

The same applies to one unable to prostrate. For example, a person may have undergone an operation on his eyes and be able to bow, stand, and sit, but unable to prostrate except by gesturing. He may not lead as imam one able to prostrate, though he may lead one unable to do so.

The underlying reason is the same as that concerning one unable to bow.

His statement, “or sit,” means that the imamate of one unable to sit is not valid except when leading someone like himself.

The underlying reason is the same as that previously mentioned regarding one unable to bow or prostrate.

His statement, “or stand,” means that one unable to stand may not lead as imam one who is able to stand.