Macbeth's reaction to the witches' prophecy for his future is that he is excited at the prospect of becoming king but also fearful about what role he will have to play in making it happen
Explanation:
In Act 1, Scene 3, the three witches greet Macbeth as the king to be and start telling him the prophecy of his future where he will be the new king. Macbeth having heard that his deepest and most incredible dream will become true starts to go from excitement to worry as he thinks about what is it going to happen for him to become the king. And little by little he starts losing his mind and to act erratically.