מִבֶּ֨ן שְׁלֹשִׁ֤ים שָׁנָה֙ וָמַ֔עְלָה וְעַ֖ד בֶּן־חֲמִשִּׁ֣ים שָׁנָ֑ה כָּל־בָּא֙ לַצָּבָ֔א לַעֲשׂ֥וֹת מְלָאכָ֖ה בְּאֹ֥הֶל מוֹעֵֽד׃
Da idade de trinta anos para cima até os cinquenta anos, todo aquele que entra no serviço para fazer o trabalho na Tenda do Encontro.
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.