Reference: Fataawa al-Lajnah ad-Daa.imah lil-Buhooth al-‘Ilmiyyah wal-Iftaa. – Question No.1 of Fatwa No.1583
Question: Is it correct that the one who shaves off his beard is cursed and that his salaah is unacceptable. If so, what is the evidence for this?
Response: All Praise is for Allaah the One, and prayers and salutations upon His Messenger, upon his family and his companions. To proceed…
Allowing the beard to grow is obligatory due to that which the Prophet ﷺ commanded. The basic rule is that a command implies an obligation. Therefore, shaving off the beard is impermissible (haraam) for that which exists therein of resembling the disbelievers and opposing the command of the Prophet ﷺ to leave the beard and let it grow. The Prophet ﷺ forbade this and commanded differing from them (i.e. the disbelievers).
On the authority of Ibn ‘Umar (radhi-yAllaahu ‘anhumaa), the Prophet ﷺ said:
«Differ from the mushrikoon and leave the beards [to grow] and trim the moustaches». Transmitted by Ahmad, al-Bukhaaree and Muslim.
Also, on the authority of Abu Hurayrah (radhi-yAllaahu ‘anhu), the Messenger of Allaah ﷺ said:
«Trim the moustaches and leave the beards [to grow] and oppose (differ) from the magians». Transmitted by Ahmad and Muslim.
It is not established in any authentic narration that the Prophet ﷺ used to trim his beard from the sides of the face and nor it’s length. However, leaving the beard to grow is not a condition for the correctness of the salaah. Whoever shaves off his beard and prays, then his prayer is not void. However, he is a sinner for abandoning an action which the Messenger of Allaah ﷺ has commanded thus opposing his guidance. As for the Prophet ﷺ having cursed the like, then we do not know of the authenticity of this.
And with Allaah lies all success and may Allaah send prayers and salutations upon our Prophet ﷺ and his family and his companions.