In the book of Rav Yeva Sava, he said that the beginning of the beard is from the supernal Chessed because the Sefirot begin with Chessed as it is written in 1 Chronicle 29:11
“לְךָ יְהוָה הַגְּדֻלָּה וְהַגְּבוּרָה וְהַתִּפְאֶרֶת, וְהַנֵּצַח וְהַהוֹד, כִּי-כֹל, בַּשָּׁמַיִם וּבָאָרֶץ: לְךָ יְהוָה הַמַּמְלָכָה, וְהַמִּתְנַשֵּׂא לְכֹל לְרֹאשׁ.”
“Yours, O YHVH is the greatness (Chessed) and the power (Gevurah) and the glory (Tiferet) and the victory (Netzach) and the majesty (Hod), indeed everything (Yessod) that is in the heavens and the earth (Malchut); Yours is the dominion, O YHVH, and You exalt Yourself as head overall.”
The Zohar accepts that but adds that the source of the Light for the beard starts in Chokmah to make the three columns of Chokmah, Chessed, Netzach on the Right, Binah, Gevurah, and Hod on the Left, and Da’at, Tiferet, and Yessod in the center.
When the world needs mercy, the Holy Mazal that is the beard of Arich Anpin is revealed, and all the lights in the beard of Zeir Anpin are filled with Light of Mercy. When the world draws judgments, vengeance is taken against those who hate and cause pain to the children of Israel.
The Light that is revealed in the beard depends on the center column of the beard that is DT”Y (Da’at, Tiferet, and Yessod).
The hair of the beard of Zeir Anpin is rough and strong because it subdues the judgments when the Holy Mazal appears.
At times of war, this beard looks like a mighty courageous hero, triumphant in war.
The beard represents the flow of light from the highest levels. For that reason, men that are aspects of Zeir Anpin, keep the beard on the face.
The Baba Sali, Rabbi Israel AbuChatzeira never cut his beard. He said that it gave him extra ability to connect higher. He was known as a miracle worker. He made those who were closed to him to grow beards.
One of his disciples came one day with a shaved beard and gave an excuse that his wife forced him to shave. The Baba Sali told him to tell his wife that if she doesn’t let him grow a beard, he will make her grow one. The wife knew the powers of the Baba Sali and never said again anything about the beard of her husband.