(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).
Some commentators feel that the king described here as the King of Arad was in fact Sichon the King of the Emorites and the reason he is referred to here as “the Canaanite” is that that every Emorite is also a Canaanite by definition.
Our sages in Rosh Hashanah 3 say that the news which the Canaanites had heard was that Aaron had died and that the protective clouds above the camp of the Israelites had disappeared. This is the meaning of 20,29: “the whole congregation saw that Aaron had died.” How could they all have seen it? They had not climbed Hor Hahar! They noticed that the cloud had disappeared and they realized that its presence had been due to Aaron’s merit. Up until that time the encampment of the Israelites had not been visible to the other nations at all. Rabbi Avohu said that instead of reading the word ויראו, “they saw,” it could be read וַיֵרָאוּ with the vowels tzeyre and kametz, and the meaning would be: “they had become visible.” Tanchuma also writes in that vein, i.e. the Jewish people now looked like a woman whose head-covering had been removed.
is from a book by Rebbe Nachman of Breslov composed around 1810....by then head-covering had become a normal Jewish thing (for men).