1. The beard should be lengthened up to one fist length. It is impermissible for one to shave the beard or trim it less than a fist length.
عن عبد الله بن عمر عن النبي صلى الله عليه وسلم قال خالفوا المشركين وفروا اللحى وأحفوا الشوارب وكان ابن عمر إذا حج أو اعتمر قبض على لحيته فما فضل أخذه (بخاري رقم 5892)
Hadhrat Abdullah bin Umar (Radhiyallahu Anhuma) reports that Rasulullah (Sallallahu Alaihi Wasallam) said, “Oppose the mushrikeen (polytheists) by lengthening the beard and shortening the moustaches.” On the occasion of Hajj or Umrah, Hadhrat Abdullah bin Umar (Radhiyallahu Anhuma) used to trim the hair of his beard that was more than a fist length.