וַיְצַוֶּ֣ה הַמֶּ֔לֶךְ אֵ֛ת עֶֽבֶד־מֶ֥לֶךְ הַכּוּשִׁ֖י לֵאמֹ֑ר קַ֣ח בְּיָדְךָ֤ מִזֶּה֙ שְׁלֹשִׁ֣ים אֲנָשִׁ֔ים וְֽהַעֲלִ֜יתָ אֶֽת־יִרְמְיָ֧הוּ הַנָּבִ֛יא מִן־הַבּ֖וֹר בְּטֶ֥רֶם יָמֽוּת׃
Rashi on Jeremiah
thirty men Since they were weakened by the famine, all of them were required.