Numbers 3:11

וְנָתַתָּה אֶת־הַלְוִיִּם לְאַהֲרֹן וּלְבָנָיו נְתוּנִם נְתוּנִם הֵמָּה לוֹ מֵאֵת בְּנֵי יִשְׂרָאֵֽל

And thou shalt give the Levites unto Aaron and to his sons; they are wholly given unto him from the children of Israel.

וְאֶת־אַהֲרֹן וְאֶת־בָּנָיו תִּפְקֹד וְשָׁמְרוּ אֶת־כְּהֻנָּתָם וְהַזָּר הַקָּרֵב יוּמָֽת

And thou shalt appoint Aaron and his sons, that they may keep their priesthood; and the common man that draweth nigh shall be put to death.’

וַאֲנִי הִנֵּה לָקַחְתִּי אֶת־הַלְוִיִּם מִתּוֹךְ בְּנֵי יִשְׂרָאֵל תַּחַת כָּל־בְּכוֹר פֶּטֶר רֶחֶם מִבְּנֵי יִשְׂרָאֵל וְהָיוּ לִי הַלְוִיִּֽם

’And I, behold, I have taken the Levites from among the children of Israel instead of every first-born that openeth the womb among the children of Israel; and the Levites shall be Mine;

כִּי לִי כָּל־בְּכוֹר בְּיוֹם הַכֹּתִי כָל־בְּכוֹר בְּאֶרֶץ מִצְרַיִם הִקְדַּשְׁתִּי לִי כָל־בְּכוֹר בְּיִשְׂרָאֵל מֵאָדָם עַד־בְּהֵמָה לִי יִהְיוּ אֲנִי יְהוָֽה

for all the first-born are Mine: on the day that I smote all the first-born in the land of Egypt I hallowed unto Me all the first-born in Israel, both man and beast, Mine they shall be: I am the LORD.’ .