Reference for Numbers 1:28

לִבְנֵ֣י יִשָּׂשכָ֔ר תּוֹלְדֹתָ֥ם לְמִשְׁפְּחֹתָ֖ם לְבֵ֣ית אֲבֹתָ֑ם בְּמִסְפַּ֣ר שֵׁמֹ֗ת מִבֶּ֨ן עֶשְׂרִ֤ים שָׁנָה֙ וָמַ֔עְלָה כֹּ֖ל יֹצֵ֥א צָבָֽא׃

Of the children of Issachar, their generations, by their families, by their fathers’houses, according to the number of names, from twenty years old and upward, all that were able to go forth to war;

BDB