Kitab-i-Aqdas/Elder44

Do not shave your heads. God has adorned them with hair. In that there are certainly signs to him who considers the requirements of nature (al-tabi'a) from the standpoint of the Possessor of Mankind.

Indeed, He is the Mighty, the Wise. It is not fitting to go beyond the limits of the ears. [note 4] This is what the Master of the worlds commanded.