To mourn a mischief that is past and gone
Is the next way to draw new mischief on.

– William Shakespeare

Othello, Act 1, Scene 3. The Duke of Venice is talking to Desdemona’s father Brabantio, Desdemona, and Othello. He is trying to smooth things out between Brabantio and the young couple after Brabantio publically disowned Desdemona. It is useless to hold onto a grudge, he counsels.