Does shaving the beard during the day in Ramadan invalidate the fast?

Shaving the beard is prohibited, whether in Ramadan or at other times, due to the authentic and explicit Hadiths commanding its growth, such as the Prophet's (peace be upon him) saying: "Be different from the polytheists: grow your beards and trim your mustaches." Ibn Hazm mentioned the consensus that trimming the mustache and growing the beard is obligatory.

Shaving the beard does not invalidate the fast, but it diminishes the reward of the fasting person, just like all other sins such as lying and backbiting. Fasting was legislated for piety, and piety is the avoidance of prohibitions. The Prophet (peace be upon him) said: "Whoever does not abandon false speech, and acting upon it, and ignorance, Allah has no need for him to abandon his food and drink." Therefore, it is incumbent upon the fasting person to avoid prohibited words and actions. If he does not avoid them, his actions do not invalidate the fast, but they diminish his reward and may cause him to lose it.