Othello act 4 scene 1 analysis

OTHELLO:
She is protectress of her honor too.
May she give that?
IAGO:
Her honor is an essence that's not seen;
They have it very oft that have it not.
But, for the handkerchief -
OTHELLO:
By heaven, I would most gladly have forgot it.
Thou said'st - Oh, it comes o'er my memory
As doth the raven o'er the infectious house,
Boding to all - he had my handkerchief.
IAGO:
Ay, what of that?
OTHELLO:
That's not so good now" (Othello 4.1 14-24).

this is when Othello and Iago are discussing Cassio having Othello's hankerchief and the way he feels about it. Othello uses the metaphor 'as doth the raven o'er infectious house' to convey the hankerchief as an omen to all. Iago also uses the metaphor 'her honor is an essence that's not seen' to say that most women who won't appear to have honor, do. this passage also foreshadows that much more trouble will come with the hankerchief.