Fear of the King
“The mother of Rav Naḥman son of Yitsḥaq was told by Chaldeans [i.e., astrologers], ‘Your son will be a thief.’ [Thus] she did not let him [go] bareheaded, saying to him, ‘Cover your head so that the fear of heaven may be upon you, and pray’—now, he did not know why she spoke that to him. One day he was sitting and studying under a palm tree, the evil impulse overcame him, he climbed up and bit off a cluster with his teeth” (BT Shabbat 156b).
“The wise has his eyes in his head, and the fool walks in darkness (Ecclesiastes 2:14). Now, where are a person’s eyes if not in his head? Perhaps in the trunk of his body or in his arms? Does this distinguish the wise one from all inhabitants of the world? Ah, but the verse surely means as follows. For we have learned: A person should not walk four cubits with his head uncovered. Why? Because Shekhinah rests upon his head. Every wise person has his eyes and his words בְּרֹאשׁוֹ (be-rosho), on his head—focused on the one who is resting and appearing on his head. When his eyes are there, he know that the light kindled on his head needs oil. For the human body is a wick, and a light is kindled above, and King Solomon exclaimed: Let oil on your head not be lacking (Ecclesiastes 9:8); for the light on one’s head needs oil, namely good deeds. Thus, the wise one has his eyes on his head—and nowhere else!” (Zohar 3:187a).
“Only בְּצֶלֶם (be-tselem), with an image, does a man goes about (Psalms 39:7) [cf. Zohar 1:218a; 3:43a-b]. Because [צֶלֶם (tselem), an image (i.e., Shekhinah)] is over a man’s head, man is prohibited to walk four cubits with his head uncovered. If She departs from over his head, his life is immediately gone” (Zohar 3:121b, Ra’aya Meheimna Naso).
“Because the Shekhinah is over his head the Masters of Mishnah taught: A scholar of the Law is forbidden to walk four cubits with his head uncovered [cf. BT Qiddushin 31a] because, the whole earth is full of His glory (Isaiah 6:3). And even more so to go with uncovered head during a blessing or the mention of the Holy Name! [And the reason for the prohibition of going with an uncovered head:] י (yod) of יהוה (YHWH) is enveloped in אוֹר (or), light, and becomes אֲוִיר (avir), atmosphere [lit., air], since י (yod), which is Ḥokhmah, is in the אֲוִיר (avir), atmosphere [cf. BT Baba Batra 158b; Tiqqunei ha-Zohar 5]. And this is the light with which He enveloped himself when He created the world, as it is written: Wrapped in light like a cloak, stretching out heavens like a tent-cloth (Psalms 104:2). Thus Let there be אוֹר (or), light (Genesis 1:1) is, Let there be אֲוִיר (avir), atmosphere. And the Masters of the Secrets of Torah taught: Before anything else was formed, הָהַוָיוֹת (ha-havayot), the existences, were formed. Thus: Let there be light, and there was light—that had existed previously” (Zohar 3:245a, Ra’aya Meheimna Pineḥas, cf. Tiqqunei ha-Zohar 37b).