Q: What is the ruling on trimming the beard to be at the same length?
A: It is obligatory to let the beard grow without cutting it, for it is authentically reported that the Prophet (peace be upon him) stated: Trim closely the moustache and let the beard grow to be contradictory to the Mushriks (those who associate others with Allah in His Divinity or worship). Reported by Imams AlBukhari and Muslim on the authority of Ibn `Umar, (may Allah be pleased with both of them).It is related by AlBukhari on the authority of Ibn `Umar(may Allah be pleased with them) that the Prophet (peace be upon him) stated: Trim closely the moustache and let the beard grow to be contradictory to the Mushriks. It is also related by Muslim on the authority of Abu Hurayrah(may Allah be pleased with him) that the Prophet (peace be upon him) stated: Trim closely the moustache, and grow the beard, and thus act against the Magians.
In doing so, one adopts the practice of the Prophet (peace be upon him) and his Companions (may Allah be pleased with them), contradicts the Mushriks, and avoids any resemblence to them and to women. As for what was reported byAlTirmidhi(may Allah be merciful with him) that the Prophet (peace be upon him) used to shave parts of the width and the length of his beard, this is a false report that was not authentically reported from the Prophet (peace be upon him). Some people rely on it, though it is not an authentic report, for its Sanad (chain of narrators) includes `Umar ibn Harun AlBalkhi who is accused of lying.
The Mu'min (believer) should not consider such false Hadith or take Rukhsah (concession) from the sayings of some people of knowledge, for the Sunnah (whatever is reported from the Prophet) should prevail over all. Allah (Glorified and Exalted be He) states: He who obeys the Messenger (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ), has indeed obeyed Allâh And: Say: "Obey Allâh and obey the Messenger, but if you turn away, he (Messenger Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ) is only responsible for the duty placed on him (i.e. to convey Allâh'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)."
He (Glorified be He) states: O you who believe! Obey Allâh and obey the Messenger (Muhammad ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ), and those of you (Muslims) who are in authority. (And) if you differ in anything amongst yourselves, refer it to Allâh and His Messenger (ﺻﻠﻰ ﺍﷲ ﻋﻠﻴﻪ ﻭﺳﻠﻢ), if you believe in Allâh and in the Last Day. That is better and more suitable for final determination. May Allah grant us success!