《孔子家语·本命解》
鲁哀公说： 男子十六岁精气通畅，女子十四岁才能生育，这时就可以生小孩了。
公曰： 男子十六精通，女子十四而化，是则可以生民矣。
Duke Ai of Lu said: When a boy is sixteen, he is sexually viable, while a girl has the ability to bear children from fourteen, and by this time they should be able to have children.