What you have done to this point cannot be undone. What you do next… It is still unwritten.
What is already woven cannot be undone. It will not make the trees grow again for you to bring the building down on our heads.
The whole point of getting things done is knowing what to leave undone
What Reason weaves, by Passion is undone.
What is right to be done cannot be done too soon.
Nothing deserves to be undone, doubtless because nothing deserved to be done.
To have left undone what thou shouldst have done: to have lost the faithfulness, the reverence, the modesty that is in thee!
Demetrius: Villain, what hast thou done?
Aaron: That which thou canst not undo.
Chiron: Thou hast undone our mother.
Aaron: Villain, I have done thy mother.
What is done cannot be undone, but one can prevent it happening again.
Whatever can be done, can be undone.