Not poppy, nor mandragora,
Nor all the drowsy syrups of the world,
Shall ever medicine thee to that sweet sleep
Which thou owedst yesterday.
– William Shakespeare
Othello, Act 3, Scene 3. Iago predicts that Othello will never enjoy a peaceful night’s sleep again, even with the help of all the medicines in the world. This is because Othello is so unsettled by the doubts about Desdemona’s fidelity planted in his mind by Iago.