大人は赤子の心を失わず（たいじんはせきしのこころをうしなわず）

Japanese vocabulary

Meaning: great human beings never lose the innocence of childhood; a virtuous ruler never loses the spirit of the common people

See it used in real works

• Example sentences from Japanese novels & web fiction (Massif)
• Hear “大人は赤子の心を失わず” pronounced in real videos (YouGlish)