Ay, sir, all this is so: but why Stands Macbeth thus amazedly? Come, sisters, cheer we up his sprites, And show the best of our delights: I'll charm the air to give a sound, While you perform your antic round: That this great king may kindly say, Our duties did his welcome pay. In a short paragraph of 100-150 words, explain the literary device that Shakespeare uses in the passage and why it is effective. Justify your answer with evidence.