People often use Du Fu's phrase "sneak into the night with the wind, moisten things quietly" to describe the teacher's obscure and subtle cultivation of students.

It means: the spring rain falls quietly at night with the spring breeze, moistening everything in the earth silently. Nowadays, in many places, "keeping things quiet" is used to describe educators who enable the educated to receive education and cultivate their sentiments in a subtle way.

Whole poem:

Delighting in Rain on a Spring Night

Author: Du Fu

Good rain knows the season, when spring comes. Sneak into the night with the wind, moisten things silently.

The wild path is dark, and the river is bright. Look at the red and wet place, the flowers in Jinguancheng are heavy.