v. phr. , literary To be kind or helpful to someone who has done wrong to you, so that he is ashamed. Alice heaped coals of fire on Mary's head by inviting her to a party after Mary had gossiped about her. Jean Valjean stole the Bishop's silver, but the Bishop heaped coals of fire on his head by giving the silver to him.
HEAP COALS OF FIRE ON ONE'S HEAD
Meaning of HEAP COALS OF FIRE ON ONE'S HEAD in English
American idioms English vocabulary. Английский словарь американских идиом. 2012