This should refer to sincerity and sincerity.
Sincerity, faith. ——"Guangya·Exegesis 1"
To be sincere is to be sincere. ——"The Sound and Meaning of All Sutras" quoted from "Popular Texts"
Be diligent and conscientious. ——"Book of Han·Biography of Sima Qian". Master Gu said: "Sincerity, sincerity."
Also obedient and sincere. ——"The Biography of Liu Yi" by Li Chaowei of the Tang Dynasty