כִּ֣י בְדִבְרֵ֤י דָוִיד֙ הָאַ֣חֲרֹנִ֔ים הֵ֖מָּה מִסְפַּ֣ר בְּנֵי־לֵוִ֑י מִבֶּ֛ן עֶשְׂרִ֥ים שָׁנָ֖ה וּלְמָֽעְלָה׃
For by the last ordinances of David the sons of Levi were numbered from twenty years old and upward.
I Chronicles
And the Levites were counted from thirty years old and above, and their number by their heads was thirty-three thousand men.