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.
Read halakhic rulings (Jewish law) on I Chronicles 23:27: and classical halakhic sources.