with certainty
To be sure, the Chinese idiom, Pinyin is y á nzh ī Z á oz á o, which is used to describe speech with real evidence, not empty words. From notes of Yuewei thatched cottage - luanyang Xiaoxia Lu 4.
The origin of Idioms
In the notes of Yuewei thatched cottage written by Ji Yun of the Qing Dynasty, "the Confucians of the Song Dynasty talk about heaven according to reason; they say that they are poor, and that they are the foundation of yin and Yang; they are in the sun and the moon and five stars; their words are solid, and they are like the palm of your hand."
Analysis of Idioms
Antonym: to catch a shadow, to build a castle in the air, to seek a moon in the water
Idiom usage
In Pu Songling's strange tales from a lonely studio, Duan Shi of Qing Dynasty: "a firm word can be believed."
with certainty
unable to profit from what one has read - tú dú fù shū