Notes The last act brings about the catastrophe of the play. This does not consist merely in the death of Macbeth upon the field of battle. Shakespeare is always more interested in the tragedy of the soul than in external events, and he here employs all his powers to paint for us the state of loneliness and hopeless misery to which a long succession of crimes has reduced Macbeth. Still clinging desperately to the deceitful promises of the witches the tyrant sees his subjects fly from him; he loses the support and companionship of his wife, and looks forward to a solitary old age, accompanied only by "curses, not loud, but deep." It is not until the very close of the act, when he realizes how he has been trapped by the juggling fiends, that Macbeth recovers his old heroic self; but he dies, sword in hand, as befits the daring soldier that he was before he yielded to temptation.
It is worth noting how in this act Shakespeare contrives to reengage our sympathies for Macbeth. The hero of the play no longer appears as a traitor and a murderer, but as a man oppressed by every kind of trouble, yet fighting desperately against an irresistible fate. His bitter remorse for the past and his reckless defiance of the future alike move us with overwhelming power, and we view his tragic end, not with self-righteous approval, but with deep and human pity.
Explanation She stills sees the blood of the murders on her hands. This is the opposite of when she said 'A little water clears us of this deed' (Page 29 - Line 70). Macbeth also questions whether his hands will ever be clean again immediately after killing Duncan, asking 'will all great Neptune's ocean wash this blood clean from my hand?' (Page 28 - Line 63). Ultimately, however, Shakespeare shows that neither a 'little water' nor an 'ocean' will wash away their guilt.
here are two quotes and notes hope they help