忍心 (rěn xīn): to have the heart to do sth; to steel oneself to a task

Seeing the child crying so sadly, she really couldn't bear to leave him alone at home.

How could he have the heart to refuse an old person who needs help so much?

Although I was very busy with work, I couldn't bear to disappoint my parents, so I still took leave and went home to spend the holiday with them.

Do you have the heart to watch these stray cats suffer from hunger and cold in the freezing winter?