"Is this a dagger which I see before me, the handle toward my hand?" This is a line from which Shakespearean play?

These lines are from Act 2, Scene 1 of William Shakespeare play, Macbeth. Here, Macbeth is experiencing what might be a moral crisis. He knows he is about to kill Duncan, but he is imagining what it will be like to actually hold the dagger and commit a murder.

In the end while Duncan is asleep, Macbeth stabs him. Despite his doubts and a number of supernatural portents, including a hallucination of a bloody dagger, Macbeth does act. But he is so shaken that Lady Macbeth has to take charge. In accordance with her plan, she frames Duncan's sleeping servants for the murder by placing bloody daggers on them.

In this situation, Macbeth is neither a born criminal nor a villain by nature. He is turned into a criminal by faulty rationalizations, by deductions from false premises, and by his own actions with others.