"double, double toil and trouble. Fire burn and cauldron bubble."- witches, Act 4 Scene 1
rhyming mimics chanting which can be associated with the supernatural witches often speak like this when something evil is about to occur symbolizing that
"Be bloody, bold, and resolute; laugh to scorn the power of man, for none of woman born shall harm Macbeth"- witches, Act 4 Scene 1
another apparition from the witches (supernatural)witches tricking Macbeth into thinking he is invincible however he is not as Macduff was born by cesarean witches never wanted Macbeth as king but instead stayed to encourage evil
"fair is foul and foul is fair"- witches, Act 1 Scene 1
rhythmic, chant-like lines means things are reversed means things that look pretty ("fair") will become ugly ("foul") and things that are ugly will become beautiful. The witches are referring first to themselves. They look ugly, but the predictions they offer are beautiful to Macbeth