וַעֲלֵיהֶ֨ם לְתֹלְדוֹתָ֜ם לְבֵ֣ית אֲבוֹתָ֗ם גְּדוּדֵי֙ צְבָ֣א מִלְחָמָ֔ה שְׁלֹשִׁ֥ים וְשִׁשָּׁ֖ה אָ֑לֶף כִּֽי־הִרְבּ֥וּ נָשִׁ֖ים וּבָנִֽים׃
And with them, by their generations, after their fathers’houses, were bands of the host for war, six and thirty thousand; for they had many wives and sons.
Read midrashic interpretation of I Chronicles 7:4: and classical rabbinic exegesis.