This is the source:
Qing Dynasty Zeng Guofan's "Family Instructions Yu Jize": "Your shortcomings are that your speech is not dull, your behavior is not dignified, you cannot read deeply, and your composition is not impressive. Rong. If you can work hard on these three things, advance vigorously, and persevere, you will not realize it in just one or two years. "Zeng Guofan's "Family Instructions Yu Jize" of the Qing Dynasty: "Your shortcoming is that you are blunt in speech. If you can work hard on these three things and persist in your behavior, you will not realize your progress in just one or two years."