Praise be to Allaah. 

The Sunnah of the Messenger of Allaah (peace and blessings of Allaah be upon him) indicates that it is obligatory to let the beard grow and that it is haraam to shave it or cut it. It was narrated in al-Saheehayn that the Prophet (peace and blessings of Allaah be upon him) said: “Cut the moustache and let the beard grow; be different from the mushrikeen.” (al-Bukhaari, al-Libaas, 5442; Muslim, al-Tahaarah, 382) 

There are many ahaadeeth which say the same as this hadeeth, indicating that it is obligatory to leave the beard alone and let it grow and that it is haraam to shave it or cut it. Whoever claims that letting the beard grow is no more than a Sunnah for which a person may be rewarded and the one who does not do it will not be punished is going against the saheeh ahaadeeth. The report that says that the Prophet (peace and blessings of Allaah be upon him) used to trim the length and breadth of his beard is a false hadeeth. But it should be noted that Islam is the religion of beauty, as it was narrated in the hadeeth, “[A man said,] ‘What if a man likes his clothes and his shoes to look good?’ The Prophet (peace and blessings of Allaah be upon him) said, ‘Allaah is Beautiful and loves beauty.’” (Narrated by Muslim, al-Eemaan, 131). The Prophet (peace and blessings of Allaah be upon him) commanded [one of his companions] to change grey hair, when he said, “Change this grey hair, but avoid black.” (Narrated by Muslim, Kitaab al-Libaas wa’l-Zeenah, 2102). The Prophet (peace and blessings of Allaah be upon him) recommended combing hair, and said, “Whoever has hair, let him take care of it.” (Abu Dawood, Kitaab al-Tarajjul, 3632. Al-Albaani said in Saheeh Sunan Abi Dawood: it is hasan saheeh. Hadeeth no. 3509). Al-Haafiz Ibn Hajar said: “Ibn Battaal said: combing means tidying the hair of the head and beard, and oiling it.” This is the Sunnah of the Prophet (peace and blessings of Allaah be upon him), and he (peace and blessings of Allaah be upon him) said, “Whoever turns away from my Sunnah has nothing to do with me.” (Narrated by al-Bukhaari, al-Nikaah, 4675) 

It should be noted that the beauty referred to is shar’i or Islamic beauty (beauty as prescribed in Islam), and not the so-called beauty which appeals to sick minds which are enamoured of kaafir fashions and the appearance of corrupt people such as male and female actors and singers, or fashion models. Hence when some people were misled by those immoral western women who pluck or shave or draw their eyebrows, or make their nails long (like wild beasts), or have tattoos, and thought that this is beauty, many Muslim women imitated them in these things, even though they are forbidden by sharee’ah. The point is not what is fashionable in the east or the west, the point is the sharee’ah which advocates wearing perfume (for men), keeping clean, dressing nicely, combing the hair, changing grey hair, and other kinds of beautification which are prescribed in Islam. And Allaah is the Source of strength.