How strange, how hellish (God forgive me for saying so!) it seems that she should love him. But, does she love him? Can she love him? Could she love him if she knew all? Know him she shall before she marries him. For the present, be still, my heart.
1986, Priscilla Scherer, "Reflections: Daytime Drama," The American Journal of Nursing, vol. 86, no. 1, p. 106:
Roll tape! Action!
"I can't feel a pulse!" shouts Ms. Brunette Beauty, RN.
Calling her installation "information as art," Hesh will have 28 separate documents and artifacts on view, one of which is—be still my heart—a stack of old newspapers.
Usage notes
In traditional English, this expression was often considered poetic or literary.
In contemporary English, the expression is usually used sarcastically to imply that a situation is not nearly as exciting as has been suggested.