以小人之心，度君子之腹

Etymology
Its form is based on this optative statement by Yan Mo (閻沒) and Ru Kuan (女寬) to Wei Shu (魏舒), to subtly advise him not to take bribes (in , Zhao 28):

Its meaning is based on this rhetorical question by, who alluded to his - an inferior's - own inability to gauge his superiors' minds, to subtly urge Shusun Zhouchou (叔孫州仇) and Meng Yizi (孟懿子) to fight (in Zuozhuan, Ai 11):

The combination of form (with slight differences) and meaning is attested in a saying attributed to Yu Ai (in ):

Idiom

 * 1) to be cynical; to be skeptical of the integrity, sincerity, or motives of others