This sentence comes from the Book of Changes, which means to cultivate integrity and innocence from an early age, which is the only way for a saint to succeed.

Source:

"Xun" said: Meng, there is danger under the mountain, and the danger stops, Meng. Meng Heng, YiHeng China Travel Service. I begged Meng Tong, Meng Tong begged me, and I should make up my mind. Early warning, just also. Repeatedly blaspheme, blaspheme is not to sue, blaspheme is also. Moral education is also a sacred work.

Translation:

Ignorance is like encountering obstacles at the foot of a mountain, knowing the danger will stop. Divination symbolizes success because timing is very important. I shouldn't ask those children who are not sensible to receive pre-school enlightenment education, but children should ask me for advice. Enlighten those children who are sincere at first, because they are resolute and conform to the doctrine of the mean. Rejecting those students whose thoughts are changeable and blasphemous violates the original intention of enlightenment. It is to cultivate integrity and innocence for childhood and is the only way for saints to succeed.

Extended data:

China people have attached great importance to enlightenment education since ancient times, and generally call their own enlightenment schools their alma mater, which shows their high status. In the long history of the Chinese nation, there are many excellent enlightenment books, among which the most outstanding ones are Saint Amethyst, Hundreds of Surnames, Thousand-character Works, Poems of a Thousand Families, Disciples' Rules, I Ching and so on.

The Book of Changes understands and grasps the world from a holistic perspective, and regards man and nature as an organic whole that is mutually inductive, that is, "the unity of man and nature". The Book of Changes has long been used as a "soothsayer". "Divination" is to predict the development of future events, and The Book of Changes is a book that summarizes the laws and theories of these predictions. The Book of Changes is an outstanding representative of China culture. Vast, subtle and all-encompassing, it is also the source of Chinese civilization. Its content involves philosophy, politics, life, literature, art, science and many other fields, and it is the first of the common classics of Confucianism and Taoism.

References:

Baidu encyclopedia-biography

References:

Baidu encyclopedia-enlightenment education