How accurate is the statement that the disagreement regarding how to trim the mustache applies to the beard, such that only shaving it completely is forbidden, while its fundamental existence remains?

The deduction of an association in ruling from an association in wording, known as dalālat al-iqtirān (implication by association), is a point of contention among legal theoreticians, with the majority rejecting it.

As for the meaning of "letting the beard grow" (i‘fāʾ al-liḥyah), scholars have differed regarding it: Some hold that it means leaving it to grow long without trimming it, while others believe in taking from what exceeds a handful. Some disliked interfering with it at all, except during Hajj or Umrah.

Al-Shawkani stated that an association in wording does not necessitate an association in ruling. Al-Nawawi pointed out that "letting the beard grow" means to make it abundant, and that it was the custom of the Persians to trim their beards, so the Sharia prohibited that.

As for Al-Qurtubi, he holds that "letting the beard grow" means making it abundant and plentiful, and that it is impermissible to shave it, pluck it, or trim a significant portion of it. However, taking from what disfigures it or leads to ostentation is good.

The Permanent Committee has preferred the view that the meaning of "letting the beard grow" is to leave it until it becomes plentiful and is not trimmed. This is the guidance of the Prophet (peace be upon him), and it is absolute letting grow.