Is shaving the beard forbidden based on the general prophetic command, "Let grow, lengthen, and make abundant" [اعفوا، أرخوا، وفروا], with the understanding that a command necessitates obligation, or is it permissible to trim from it because the Prophet (peace be upon him) placed it in the category of a command, not a prohibition, and if he had intended prohibition, he would have said, "Do not shave"?

Sharia rulings are tied to ability (istita'ah). Even forbidden acts, which are prohibited by Sharia, are permissible for a servant to commit if compelled by necessity, as Allah the Almighty says: ﴿And He has already explained to you what He has forbidden to you, except for that to which you are compelled.﴾ [Al-An'am: 119].

The Hadith: "What I have forbidden for you, avoid; and what I have commanded you to do, do as much of it as you can," does not mean that the aspect of prohibition does not consider a servant's ability. Rather, refraining from what is forbidden is within one's ability, and inability to perform an act is what is qualified by ability.

All Sharia rulings are tied to ability, whether in commands or prohibitions. Obligations are waived upon inability, and when unable, one performs what is within their ability. Citing this Hadith in the matter of the beard is valid when one is unable to fulfill what is commanded by Sharia, not merely because something is a command and not a prohibition. Otherwise, one could make a similar argument for establishing prayer.