I Chronicles 25:20 Midrash

לִשְׁלֹשָׁ֤ה עָשָׂר֙ שֽׁוּבָאֵ֔ל בָּנָ֥יו וְאֶחָ֖יו שְׁנֵ֥ים עָשָֽׂר׃

For the thirteenth, Shubael, his sons and his brethren, twelve;