מִבֶּ֨ן שְׁלֹשִׁ֤ים שָׁנָה֙ וָמַ֔עְלָה וְעַ֖ד בֶּן־חֲמִשִּׁ֣ים שָׁנָ֑ה כָּל־הַבָּ֗א לַעֲבֹ֨ד עֲבֹדַ֧ת עֲבֹדָ֛ה וַעֲבֹדַ֥ת מַשָּׂ֖א בְּאֹ֥הֶל מוֹעֵֽד׃
de l’âge de trente ans et au-delà, jusqu’à l’âge de cinquante ans, tous ceux qui étaient admissibles à l’exécution d’un service ou à celle d’un transport dans la tente d’assignation:
Tosefta Shekalim (Lieberman)
A Levite may only enter the court for service if he has studied for five years, for it is said: "This applies to the Levites: from the age of twenty-five" etc. And further the [Scripture] says: ”From the age of thirty”. If it is said: “From the age of twenty-five” why is it said: ״From thirty years”? If it is said: "From the age of thirty" then why is it said: "From the age of twenty-five"? That means that he studied all the time between the age of twenty-five and thirty, from that point in time and onwards he was allowed to work From here it was said: Whoever does not show success in his instruction within five years, R. Jose says three years, because it is said: "To educate you for three years.