Praise be to Allah Alone. May Allah's Peace and Blessings be upon our Prophet Muhammad, his family, and Companions!
Some Muslim brothers asked me the following questions:
1 Is letting the beard grow obligatory or merely permissible?
2 Is it a sin or just misconduct to shave one's beard?
3 Is it permissible to shave off the beard and let mustache grow?
Following are the answers of these questions: It is authenticallyreported by AlBukhari and Muslim in the Two Sahih (authentic) Books of Hadithon the authority of Ibn `Umar (may Allah be pleased with both of them) that the Prophet (peace be upon him) said: Trim the mustache and let the beard grow and be contradictory to the unbelievers.
Moreover, it is related by Muslim in his Sahih on the authority of Abu Hurayrah (may Allah be pleased with him) that the Prophet (peace be upon him) said: Trim closely the moustache, and grow the beard, and thus act against the fireworshippers.
Furthermore, it was related by AlNasa'iy in his Sunan through an authentic chain of narrators on the authority of Zayd ibn Arqam (may Allah be pleased with him) that the Prophet (peace be upon him) said: "Whoever does not trim his moustache is not one of us."
The great and wellknown Hadith scholar Abu Muhammad ibn Hazm said: "Scholars are unanimously in agreement that trimming the moustache and letting the beard grow are obligatory."
There are many other Hadiths and scholarly discussions in this regard i.e., trimming mustache and letting the beard grow long. They are too lengthy to be quoted in this brief note. The answers of the three questions are evident from the Hadiths mentioned above and the juristic agreement cited by Ibn Hazm.
In brief, growing beards is obligatory and should not be abandoned as the Prophet (peace be upon him) ordered us to do so which indicates obligation. Allah (Glorified and Exalted be He) says: And whatsoever the Messenger (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) gives you, take it; and whatsoever he forbids you, abstain (from it).
The same is equally applied to cutting and trimming mustaches. However, trimming it closely is better. Anyway, it is by no means permissible to let it grow too much. Actually, this runs counter to the Prophet's (peace be upon him) commands: Trim closely the mustache Trim closely the moustache, and let the beard grow. Trim closely the moustache, and grow the beard, and thus act against the fireworshippers. "Whoever does not trim his moustache is not one of us."
The Prophet (peace be upon him) is authentically reported to have said all these four narrations of Hadith. The last narration said: "Whoever does not trim his moustache is not one of us." This is a severe threat and strict warning, which requires a Muslim to be on his guard against doing that which Allah (Exalted be He) and His Messenger (peace be upon him) prohibited and to proceed to do that which Allah (Exalted be He) and His Messenger (peace be upon him) commanded.
It is also inferred that letting the mustache grow too long is a sin and disobedience. Likewise, shaving and cutting the beard short is a sin and disobedience having the effect of decreasing and weakening one's faith. Moreover, it is likely to incur Allah's wrath and punishment.
Moreover, the abovequoted Hadiths indicate that letting mustaches grow and trimming beards fall under acting like the magi and disbelievers when it is wellknown that acting like them is not permissible. To this effect, the Prophet (peace be upon him) said: "Anyone who imitates a people is one of them." I hope that my answer is sufficient and convincing.
May Allah grant us success! May Peace and Blessings be upon our Prophet Muhammad, his family, and Companions!