Macbeth commands his cowardly servant to take his face out of his presence. Then he yells for Seyton who will bring Macbeth his armor for fighting. Macbeth continues to say that he is "sick at heart." He is about to go to battle. He is talking to himself. He states that this "push" or battle will either deny him the throne (take the throne from him) or bring him "cheer" as the throne will be his. This battle will decide whether he will lose the throne or remain king. This battle will decide whether Macbeth lives or dies.
If he does keep the throne, he must not expect to have love and honor from his friends or subjects (people he governs). Instead, he realizes he will have curses, but only quiet curses. People will quietly curse Macbeth for fear he will hear them. He states that he must not look to have the honor old age brings. If the people do honor him, they will only mouth the honor; they will not actually mean it. They "dare not" openly curse him for fear of Macbeth. These are Macbeth's comments:
Take thy face hence.
Seyton—I am sick at heart,
When I behold—Seyton, I say!—This push
Will cheer me ever or disseat me now.
I have lived long enough. My way of life(25)
Is fall'n into the sear, the yellow leaf,
And that which should accompany old age,
As honor, love, obedience, troops of friends,
I must not look to have; but, in their stead,
Curses, not loud but deep, mouth-honor, breath,(30)
Which the poor heart would fain deny and dare not.