All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
The Prophet ordered the Muslims to let their beards grow freely and to trim their moustache as he said: "Be different from the non-Muslims, let your beards grow and trim your moustache".
When the delegation of the king of Persia came to the Prophet they had their beards shaved and their moustache grown, thereupon the Prophet denied this and asked them: ''Who ordered you to do this? They replied: ‘‘Our lord (meaning their king) ordered us’’. Then the Prophet said: "But my Lord (Allaah) ordered me to let the beard grow and to trim the moustache".
Therefore, shaving the beard is prohibited with the exception of trimming what is beyond a fist’s length because it is reported that Ibn ‘Umar trimmed what exceeded a fist’s length from his beard after coming out of the state of Ihraam.
Allaah Knows best.