Iago and Othello view the city. Iago begins with small comments and gradually reels Othello in until he tells him point blank that Desdemona is cheating on him. “Trifles light as air Are to the jealous confirmations strong As proofs of holy writ.”(3.3) This quote shows that he observes that things that may otherwise seem insignificant are given outsized importance when they confirm an already held belief. Prior to that Othello demands proof and Iago promises to give him some .Then Iago swears that he will help Othello revenge himself on Desdemona. “O, beware, my lord, of jealousy!
It is the green-eyed monster which doth mock The meat it feeds on.” (3.3) Iago warns Othello in order to incite his jealousy, while at the same time seeming to have his best interests at heart. The idiom "green-eyed monster" comes from this line in Othello, and Iago characterizes the emotion as one that consumes the man who revels in it. Meanwhile Iago comes in with Cassio and finds Desdemona mad at Othello’s odd behavior. He promises her he will find out what is