4מִצְוַת עֲשֵׂה לַעֲשׂוֹת בְּגָדִים אֵלּוּ וְלִהְיוֹת הַכֹּהֵן עוֹבֵד בָּהֶן שֶׁנֶּאֱמַר (שמות כח ב) "וְעָשִׂיתָ בִגְדֵי קֹדֶשׁ". (שמות כט ח) "וְאֶת בָּנָיו תַּקְרִיב וְהִלְבַּשְׁתָּם כֻּתֳּנֹת". וְכֹהֵן גָּדוֹל שֶׁשִּׁמֵּשׁ בְּפָחוֹת מִשְּׁמוֹנָה בְּגָדִים אֵלּוּ אוֹ כֹּהֵן הֶדְיוֹט שֶׁשִּׁמֵּשׁ בְּפָחוֹת מֵאַרְבָּעָה בְּגָדִים אֵלּוּ הוּא הַנִּקְרָא מְחֻסַּר בְּגָדִים וַעֲבוֹדָתוֹ פְּסוּלָה וְחַיָּב מִיתָה בִּידֵי שָׁמַיִם כְּזָר שֶׁשִּׁמֵּשׁ שֶׁנֶּאֱמַר (שמות כט ט) "וְחָגַרְתָּ אֹתָם אַבְנֵט" (שמות כט ט) "וְהָיְתָה לָהֶם כְּהֻנָּה". בִּזְמַן שֶׁבִּגְדֵיהֶם עֲלֵיהֶן כְּהֻנָּתָן עֲלֵיהֶן. אֵין בִּגְדֵיהֶן עֲלֵיהֶן אֵין כְּהֻנָּתָם עֲלֵיהֶן אֶלָּא הֲרֵי הֵם כְּזָרִים וְנֶאֱמַר (במדבר א נא) (במדבר ג י) (במדבר ג לח) (במדבר יח ז) "וְהַזָּר הַקָּרֵב יוּמָת":
It is a positive commandment to make these garments and for the priests to serve in them, as [Exodus 28:2] states: "And you shall make holy garments," and [ibid. 29:8] states: "And drew near his sons and dress them in tunics." When a High Priest serves with less than these eight garments or an ordinary priest serves with less than these four garments, he is called lacking garments. His service is invalid and he is liable for death at the hand of Heaven, like a non-priest who serves. [This is indicated by ibid.:9 which states:] "And you shall gird them with a sash... and their priesthood shall be for them...." [Implied is that] when their garments are upon them, their priesthood is upon them. [Conversely,] if their garments are not upon them, they are like non-priests, concerning whom [Numbers 1:51] states: "A non-priest who draws close [to the service of the Sanctuary] shall die."