All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.
Undoubtedly, the narrations of the Prophet prove letting the beard grow freely without shortening it or trimming it, and these narrations are more worthy to abide by. However, some scholars are of the view that it is permissible to cut what exceeds a fist’s length of the beard because some of the companions did so and not only Ibn ‘Umar and also some scholars of the successors of the companions did so. Indeed, Ibn Abi Shaybah reported cutting more than a fist’s length (of the beard) from ‘Ali, Abu Hurayrah, ‘Abdullaah ibn ‘Umar, Taawoos, and Qaasim ibn Muhammad ibn Abi Bakr .
Furthermore, ‘Attaa’ ibn Abi Rabaah said: “They loved to let the beard grow freely as it is except in Hajj and ‘Umrah.”
This is indeed a considerable opinion because Abu Hurayrah and Ibn ‘Umar are among the companions who narrated the narrations about letting the beard grow freely as it is and they are the ones who cut what exceeded a fist’s length of their beards, so it is most unlikely that they did so without a religious evidence, and if one of them had forgotten, it is most unlikely that the other had also forgotten. In addition to this, ‘Ali who was a rightly guided caliph did the same.
In any case, this is a controversial issue and the heart of the believers should accept it. Therefore, if a person cuts what exceeds a fist’s length of his beard as a way of following the example of the above companions believing that they did not do so except that it was permissible because they know better about the meaning of the Prophetic narrations, then it is permissible for him to do so and he would not be sinful.
Allaah Knows best.