What is meant by the two letters in the speech of the Shafi'is, and how is their audibility measured? Is the sound produced by stifled crying or audible gasping due to it considered prohibited? And what is meant by "muqabil al-asahh" (the counter-position to the most correct), and is it permissible to adopt it?

The prayer is invalidated by intentional utterance of two letters of the alphabet, whether they are understood or not, such as uttering "qum" (stand) or "an" (from). It is also invalidated by a single understood letter, such as "qi" (protect) from "wiqāyah" (protection). Similarly, clearing the throat, laughing, crying, moaning, and blowing invalidate the prayer if two letters emerge from them; otherwise, they do not invalidate it.

The phrase "al-asahh" (the most correct) indicates the preferred opinion within the Shafi'i madhhab (definition), while its counterpoint, "as-sahih (definition)" (the correct), is less preferred but permissible to act upon due to its strength.