Ruling on one who trims his beard
Question

                What is the ruling on one who trims his beard and makes all parts of it even in length?
Praise be to Allah.It is obligatory to leave 
          the beard alone and let it grow, and not do anything to it, because 
          it was proven that the Prophet 
          
          (peace and blessings of Allaah be upon him) said: “Trim the moustache 
          and let the beard grow; be different from the mushrikeen.” (Saheeh, 
          agreed upon, narrated from Ibn ‘Umar). Al-Bukhaari (may Allaah have 
          mercy on him) narrated in his Saheeh from ‘Ibn ‘Umar (may Allaah 
          be pleased with him) that the Prophet 
          
          (peace and blessings of Allaah be upon him) said: “Cut the moustache 
          and leave the beard alone; be different from the mushrikeen.” Muslim 
          narrated in his Saheeh from Abu Hurayrah (may Allaah be pleased 
          with him) that the Prophet 
          
          (peace and blessings of Allaah be upon him) said: “Trim the moustache 
          and let the beard grow; be different from the Magians (Zoroastrians).”  
          
All of these ahaadeeth indicate 
          that it is obligatory to leave the beard alone and let it grow, and 
          that it is obligatory to trim the moustache. This is what is obligatory 
          as taught and enjoined by the Prophet 
          
          (peace and blessings of Allaah be upon him). This was the example set 
          by the Prophet 
          
          (peace and blessings of Allaah be upon him) and his companions (may 
          Allaah be pleased with them), to be different from the mushrikeen and 
          to avoid resembling them or resembling women.  
With regard to the report 
          narrated by al-Tirmidhi (may Allaah have mercy on him), that the Prophet 
          
          (peace and blessings of Allaah be upon him) used to trim something from 
          the length and breadth of his beard, this is a false report according 
          to the scholars, and it is not a saheeh report from the Prophet 
          
          (peace and blessings of Allaah be upon him). Some people clung to this 
          hadeeth to prove their point, but it is a report which is not saheeh, 
          because its isnaad includes ‘Umar ibn Haaroon al-Balkhi, who was accused 
          of lying.  
It is not permissible for 
          the believer to pay any attention to this false hadeeth, or to take 
          what some of the scholars say as a concession. The Sunnah applies to 
          everyone, and Allaah says (interpretation of the meaning):  
“He who obeys 
          the Messenger (Muhammad), has indeed obeyed Allaah” 
[al-Nisa’ 4:80]  
“Say: ‘Obey Allaah 
          and obey the Messenger, but if you turn away, he (Messenger Muhammad) 
          is only responsible for the duty placed on him (i.e. to convey Allaah’s 
          Message) and you for that placed on you. If you obey him, you shall 
          be on the right guidance. The Messenger’s duty is only to convey (the 
          message) in a clear way (i.e. to preach in a plain way)’” 
[al-Noor 24:54]  
“O you who believe! 
          Obey Allaah and obey the Messenger (Muhammad), and those of you (Muslims) 
          who are in authority. (And) if you differ in anything amongst yourselves, 
          refer it to Allaah and His Messenger, if you believe in Allaah and in 
          the Last Day. That is better and more suitable for final determination” 
          
[al-Nisa’ 4:59]