I look down towards his feet; but that’s a fable. –
If that thou be’st a devil, I cannot kill thee.
– William Shakespeare
Othello, Act 5, Scene 2. When Iago is brought before Lodovico, Othello looks down at Iago’s feet for the cloven hooves sign of the devil, then stabs him. Shocked by Iago’s wickedness and how he deceived him, Othello metaphorically compares Iago to Satan.