Another interpretation: To what may the matter be compared? To a king who entered a province and saw a handsome young man stoking the fires in the bathhouse furnace. The king said to him: Come with me, and I will place you in my palace. He went with him, and he made him an officer [pakostor]. The members of the palace said: Yesterday he was stoking the furnace, and now he is an officer! So too the Holy One, blessed be He, said: Come after Me, and I will make you a High Priest like Adam the first man. As it is stated, "And I will make you into a great nation," and it is written, "And the priest who is greatest among his brothers," and it is written, "You are a priest forever according to the order of Malki-Tzedek."
Yalkut Shimoni on Torah 63:4
Yalkut Shimoni on Torah 63:4
דָּבָר אַחֵר: לְמָה הַדָּבָר דּוֹמֶה, לְמֶלֶךְ שֶׁנִּכְנַס לִמְדִינָה, וְרָאָה בָּחוּר נָאֶה מַסִּיק בַּקָּמִין בַּמֶּרְחָץ. אָמַר לוֹ הַמֶּלֶךְ: בּוֹא עִמִּי, וַאֲנִי נוֹתֶנְךָ בַּפָּלָטִין שֶׁלִּי. הָלַךְ עִמּוֹ, וַעֲשָׂאוֹ פָּקוֹסְטוֹר, אָמְרוּ בְּנֵי פָּלָטִין: אֶתְמוֹל מַסִּיק בַּקָּמִין, וְעַכְשָׁו פָּקוֹסְטוֹר, כָּךְ אָמַר הַקָּדוֹשׁ בָּרוּךְ הוּא: בּוֹא אַחֲרַי, וַאֲנִי עוֹשֶׂה אוֹתְךָ כֹּהֵן גָּדוֹל כְּאָדָם הָרִאשׁוֹן. שֶׁנֶּאֱמַר: וְאֶעֶשְׂךָ לְגוֹי גָּדוֹל, וּכְתִיב: "וְהַכֹּהֵן הַגָּדוֹל מֵאֶחָיו", וּכְתִיב: "אַתָּה כֹהֵן לְעוֹלָם עַל דִּבְרָתִי מַלְכִּי צֶדֶק".