Torah Portion: Shemini
“ראשיכם אל תפרעו“ (ויקרא י ו)
It is a negative commandment that kohanim not enter the Sanctuary with their hair grown long, as in the manner of mourners, as it is written, Do not leave your heads unshorn (Vayikra 10:6).
Among the roots of the mitzvah is the aim of increasing the honor of the Holy Temple. It is therefore proper for us that we not enter there with long hair in the manner of mourners. This is similar to what is written in the Book of Esther: for it is forbidden to enter the king’s gate in a garment of sackcloth (Esther 4:2) — that is, it is not befitting to enter the royal palace in any manner other than joy and contentment, not in a manner of mourning and anguish. This thought reinforces the fundamental idea that we have set forth about all aspects of the House, which is that they are designed to bolster proper deeds in the hearts of people and to distance all types of improper and sinful behavior. Since this is the general idea of the Sanctuary, it is proper that we enter there in a manner of honor, awe, greatness and joy. By setting our thoughts on the stature of the place and its glory, our hearts become softened there and we become worthy of receiving all good.
This commandment applies when the Holy Temple stands, to the kohanim who serve in the Temple. One who transgressed this and entered the Holy Temple with grown hair — meaning, after letting it grow for thirty days — is liable for death at the hands of Heaven, as it is written, Do not leave your heads unshorn… that you not die (ibid.).