Avivah Gottlieb Zornberg, The Particulars of Rapture: Reflections on Exodus, New York: Doubleday, 2001, p. 369.
The High Priest's vestments invest him in anxiety, no less than in glory. Ultimately, it is not only the diadem that is to be "Holy to God," but its wearer. If the dissonance between vestment and wearer is palpable, if there is not "that within which passes show," the trappings become hollow.
(ה) תִּקּוּן הַמַּלְבּוּשִׁים כֵּיצַד. מְתַקֵּן מַלְבּוּשָׁיו תְּחִלָּה וּמְצַיֵּן עַצְמוֹ וּמְהַדֵּר שֶׁנֶּאֱמַר הִשְׁתַּחֲווּ לַה׳ בְּהַדְרַת קֹדֶשׁ. וְלֹא יַעֲמֹד בִּתְפִלָּה בַּאֲפוּנְדָתוֹ, וְלֹא בְּרֹאשׁ מְגֻלֶּה, וְלֹא בְּרַגְלַיִם מְגֻלּוֹת אִם דֶּרֶךְ אַנְשֵׁי הַמָּקוֹם שֶׁלֹּא יַעַמְדוּ בִּפְנֵי הַגְּדוֹלִים אֶלָּא בְּבָתֵּי הָרַגְלַיִם. וּבְכָל מָקוֹם לֹא יֶאֱחֹז תְּפִלִּין בְּיָדוֹ וְסֵפֶר תּוֹרָה בִּזְרוֹעוֹ וְיִתְפַּלֵּל מִפְּנֵי שֶׁלִּבּוֹ טָרוּד בָּהֶן. וְלֹא יֶאֱחֹז כֵּלִים וּמָעוֹת בְּיָדוֹ. אֲבָל מִתְפַּלֵּל הוּא וְלוּלָב בְּיָדוֹ בִּימוֹת הֶחָג מִפְּנֵי שֶׁהוּא מִצְוַת הַיּוֹם. הָיָה מַשּׂוֹי עַל רֹאשׁוֹ וְהִגִּיעַ זְמַן תְּפִלָּה אִם הָיָה פָּחוֹת מֵאַרְבָּעָה קַבִּין מַפְשִׁילוֹ לַאֲחוֹרָיו וּמִתְפַּלֵּל בּוֹ. הָיָה אַרְבָּעָה קַבִּין מַנִּיחוֹ עַל גַּבֵּי קַרְקַע וְאַחַר כָּךְ יִתְפַּלֵּל. דֶּרֶךְ כָּל הַחֲכָמִים וְתַלְמִידֵיהֶם שֶׁלֹּא יִתְפַּלְּלוּ אֶלָּא כְּשֶׁהֵן עֲטוּפִים:
(5) Adjustment of the dress. Before beginning the Service, the dress should first be adjusted and the personal appearance made trim and neat, as it is said, "O worship the Lord in the beauty of holiness" (Psalms 96:9). One should not stand in prayer wearing a moneybelt, nor bareheaded, nor barefoot, where the local custom is not to stand in the presence of the great, without shoes. And one should not pray anywhere, holding phylacteries in the hand or carrying a scroll of the law in the arms, for the mind would then be preoccupied with those sacred objects. Nor while praying, should vessels or money be held in the hand. On the feast of Tabernacles, however, the worshiper prays, while carrying a palm branch—this being the religious duty of the day. When the time comes to recite the prayer, a person carrying a burden on his head, adjusts it behind him, if it is less than four kabs**A kab is equal in volume to 4 logs. A log is equal in volume to 6 hen’s eggs. and recites the prayer. If it is four kabs in size, he places it on the ground, and then prays. The practice of all the sages and their disciples is not to pray unless their heads are wrapped in the Talith (praying shawl).