Numbers 8:23

וַיִּֽתְחַטְּאוּ הַלְוִיִּם וַֽיְכַבְּסוּ בִּגְדֵיהֶם וַיָּנֶף אַהֲרֹן אֹתָם תְּנוּפָה לִפְנֵי יְהוָה וַיְכַפֵּר עֲלֵיהֶם אַהֲרֹן לְטַהֲרָֽם

And the Levites purified themselves, and they washed their clothes; and Aaron offered them for a sacred gift before the LORD; and Aaron made atonement for them to cleanse them.

וְאַחֲרֵי־כֵן בָּאוּ הַלְוִיִּם לַעֲבֹד אֶת־עֲבֹֽדָתָם בְּאֹהֶל מוֹעֵד לִפְנֵי אַהֲרֹן וְלִפְנֵי בָנָיו כַּאֲשֶׁר צִוָּה יְהוָה אֶת־מֹשֶׁה עַל־הַלְוִיִּם כֵּן עָשׂוּ לָהֶֽם

And after that went the Levites in to do their service in the tent of meeting before Aaron, and before his sons; as the LORD had commanded Moses concerning the Levites, so did they unto them.

זֹאת אֲשֶׁר לַלְוִיִּם מִבֶּן חָמֵשׁ וְעֶשְׂרִים שָׁנָה וָמַעְלָה יָבוֹא לִצְבֹא צָבָא בַּעֲבֹדַת אֹהֶל מוֹעֵֽד

’This is that which pertaineth unto the Levites: from twenty and five years old and upward they shall go in to perform the service in the work of the tent of meeting;

וּמִבֶּן חֲמִשִּׁים שָׁנָה יָשׁוּב מִצְּבָא הָעֲבֹדָה וְלֹא יַעֲבֹד עֽוֹד

and from the age of fifty years they shall return from the service of the work, and shall serve no more;