According to the Zohar, the beard is considered to be a channel of holiness and blessing and is therefore not to be shaven or trimmed by any method.
Zohar Vol. 11 Safra Det’zniuta
Third Chapter
33. Nine precious features were granted to the beard. Everything that is hidden and not revealed is lofty and precious. THE BEARD was concealed in the Scriptures, FOR THERE IS NO MENTION OF THE BEARD SUCH AS, “THE EYES OF HASHEM,” “THE EARS OF HASHEM” AND “HIS CHEEKS ARE LIKE A BED OF SPICES” (SHIR HASHIRIM 5:13). BUT THERE IS NO MENTION OF THE BEARD, AND THAT IS BECAUSE IT IS LOFTY AND PRECIOUS.
34. The first feature of the beard: Hairs upon hairs EMERGE from before the opening of the ears to the top of the mouth, MEANING THE UPPER LIP. THE SECOND FEATURE: It is from this top OF THE LIP to the other top OF THE LIP. THE THIRD FEATURE: THERE IS a path below the two nostrils OF THE NOSE so full OF HAIR that it is invisible. THE FOURTH FEATURE: The cheeks are covered WITH HAIR on one side and the other side. THE FIFTH FEATURE: In them TWO apples OF THE FACE are seen, red as a rose. THE SIXTH FEATURE: on one thread hangs coarse black HAIR down to the chest. THE SEVENTH FEATURE: The lips are free OF HAIR and are as red as a rose.
35. THE EIGHTH FEATURE: Short HAIRS travel down the neck and cover the nape. THE NINTH FEATURE: HAIRS both long and short, HARD as sinews descend equally, MEANING THAT THEY EQUALLY MINGLE WITH EACH OTHER. One who has these nine features is mighty and strong, NAMELY ZEIR ANPIN.
36. It is written, “Out of my distress I called on Yah” (Tehilim 118:5). David recited nine clauses until “all nations compassed me about” (Ibid. 10), in order to surround HIMSELF WITH THEM and protect himself. THEY CORRESPOND TO THE NINE FEATURES OF THE BEARD OF ZEIR ANPIN. 1. “OUT OF MY DISTRESS I CALLED ON YAH.” 2. “YAH ANSWERED ME WITH LIBERATION.” 3. “HASHEM IS ON MY SIDE, I WILL NOT FEAR.” 4. “HASHEM TAKES MY PART WITH THOSE WHO HELP ME.” 5. “IT IS BETTER TO TAKE REFUGE IN HASHEM.” 6. A SECOND “IT IS BETTER TO TAKE REFUGE IN HASHEM.” TOGETHER WITH THE THREE TIMES ‘MAN’ IS MENTIONED, WHICH ALLUDE TO THREE FEATURES, THEY ARE NINE, AND THESE NINE FEATURES ARE IN THE SECRET OF THE VERSE, “And the earth, brought forth grass, herb yielding seed after its kind, and tree, yielding fruit, whose seed was in itself, after its kind” (Beresheet 1:12). These nine FEATURES OF THE BEARD were uprooted from a whole name, NAMELY FROM THE THIRTEEN FEATURES OF THE BEARD OF ARICH ANPIN, AND CAME TO ZEIR ANPIN. Afterwards, they were AGAIN planted in a complete name, as is said, “And Hashem Elohim planted”, WHICH IS THE FULL NAME OF ATIK AND ZEIR ANPIN. There are thirteen features of the Beard in the supernal one, NAMELY ARICH ANPIN. The lower, WHICH IS ZEIR ANPIN, appears in nine features OF THE BEARD, AND THIRTEEN PLUS NINE EQUALS 22. These are the 22 letters that were engraved through them.
37. Therefore, IF ONE SEES IN a dream that he was holding in his hand the beard of an important man, then he is at peace with his Master and his enemies shall be subdued under him. The upper Beard, OF ARICH ANPIN, that illuminates to the lower BEARD OF ZEIR ANPIN is more so, because the upper Beard is called ‘abundant in Chesed’, while in Zeir Anpin it is CALLED plain ‘Chesed’. When he needs light, the upper Beard then illuminates and HE TOO is called abundant in Chesed.