This sentence shows the importance of women in a family, because a good woman can really benefit three generations. If a man marries a particularly bad wife, then this wife is particularly bad to his parents and children in all aspects. Then these three generations will be hurt to varying degrees, which is a particularly annoying and distressing thing. But if you marry a good wife, she is filial to her parents and then cares about her husband. He can do his duty to his children and raise them well. So these three generations are good women. As a good woman, they can support a big family and make the whole family more harmonious, comfortable and happy. A bad woman may make a mess of the family, so there is still a lot of truth in this eternal wisdom.