Act V, Scene ii., lines 150-134
Emilia. O, who hath done this deed?
Desdemona. Nobody--I myself. Farewell. Commend me to my kind lord. O, farewell!
Othello. Why, how should she be murd'red?
Emilia. Alas, who knows?
Othello. You heard her say herself, it was not I.
Emilia. She said so. I must needs report the truth.
Othello. She's like a liar gone to burning hell! 'Twas I that killed her.
Emilia. O, the more angel she,
And you the blacker devil!
Othello. She turned to folly, and she was a whore.
Emila. Thou dost belie her, and thou art a devil.
Othello. She was as false as water.
Emilia. Thou art rash as fire to say
That she was false. O, she was heavenly true!
This dialogue is located at the end of the story--just after Othello smothered Desdemona with her pillow. Because of Othello's grief and deep love for Desdemona he did series of wrong actions.
I have to mention that because of Shakespeare's artful mastery of meter, diction, imagery, and tone the scene is matchless and captivates interest. This portion of the play is dramatic and suspenseful. The author "changed things up" and "kept the reader guessing" with regard to the structure and meter--thus causing even more suspense than what the plot had already provided.
In this group of dialogue, Othello loses his usual poetic eloquence. His mental and emotional composure were compromised, thus impairing his diction. This temporary breach in character displayed his internal conflict and how it was affecting him as a person--for Othello's dignified speech, just as the way anyone speaks, was a part of him as a person.
The images displayed in the play are very strong and that's why this scene feels very realistic when we are reading the book.