In the Torah scroll of Rabbi Meir they found written "garments of light" [katenot or, read with an aleph for the word meaning 'light' rather than 'skin']. These were the garments of the first Adam, which resembled a lantern, wide below and narrow above, smooth as a fingernail and fair as a pearl, like the fine linen vessels that come from Beit She'an. "Garments of skin" - because they clung to the skin, and in them the firstborn performed the service. Rabbi Shmuel bar Nachman said: they were of camel's wool and rabbit's wool. "Garments of skin" - because they came from skin. Rabbi Levi said: The Torah taught you proper conduct - eat according to your means. "From every tree of the garden you may eat" (Genesis 2:16), but dress less than what you eat, "And He made for Adam and for his wife garments of skin"; and spend on others more than you wear, for behold, two of them dwelt in the whole world entire.
Garments of Light and the Splendid Clothing of the First Adam
Yalkut Shimoni on Torah 34:1
בְּתוֹרָתוֹ שֶׁל רַבִּי מֵאִיר מָצְאוּ כָּתוּב כָּתְנוֹת אוֹר אֵלּוּ בְּגָדָיו שֶׁל אָדָם הָרִאשׁוֹן שֶׁהָיוּ דוֹמִין לְפָנָס רְחָבִין מִלְּמַטָּה וְצָרִין מִלְּמַעְלָה, חֲלָקִין כְּצִפּוֹרֶן וְנָאִים כְּמַרְגָּלִית, כִּכְלֵי פִּשְׁתָּן הַדַּקִּין הַבָּאִין מִבֵּית שְׁאָן. כָּתְנוֹת עוֹר, שֶׁהֵן דְּבֵקִין לָעוֹר וּבָהֶן הָיוּ הַבְּכוֹרוֹת מְשַׁמְּשִׁין. רַבִּי שְׁמוּאֵל בַּר נַחְמָן אָמַר, צֶמֶר גְּמַלִּים וְצֶמֶר אַרְנָבִים הָיוּ. כָּתְנוֹת עוֹר, שֶׁהָיוּ בָּאִין מֵעוֹר. אָמַר רַבִּי לֵוִי לִמְּדָּתְךָ תּוֹרָה דֶּרֶךְ אֶרֶץ, לְפוּם חֵילְךָ אֱכֹל (בראשית ב, טז) מִכֹּל עֵץ הַגַּן תֹּאכֵל, ופְרֶא מִן מַה דְּאַתּ לָבִישׁ "וַיַּעַשׁ לְאָדָם וּלְאִשְׁתּוֹ כָּתְנוֹת עוֹר", וְיוֹתֵר מִמַּה דְּאַתְּ שָׁרֵי שֶׁהֲרֵי שְׁנַיִם הָווּ שְׁרוּיִין בְּכָל הָעוֹלָם כֻּלּוֹ.