Does abandoning the beard lead to sin, and what is the evidence for that, and what is the difference between Sunnah and confirmed Sunnah?

Confirmed and unconfirmed Sunan fall under the category of Mandub (recommended), for which the doer is rewarded but the one who abstains is not punished. Confirmed Sunan are more emphasized. Mandub, in Islamic law, is that for which the doer is rewarded, such as the regular (ratibah) Sunnah prayers, and it is also called Sunnah, Mustahabb (desirable), Tatattu' (voluntary), Nafl (supererogatory), and Qurbah (act of drawing closer to Allah). The ruling on growing the beard has been mentioned previously.