heart of grace
/ˌhɑːt əv ˈɡreɪs/(also heart of grass) Now rare
noun
to take heart of grace(and variants): to pluck up courage; (now chiefly) to take encouragement or comfort. Compare to take heart.
- Also in extended use, with reference to things..
Origin
Early 16th century; earliest use found in Terence's Andria. Origin uncertain, as is the original form of the expression.