While Napoleon was speaking about changes on the farm with the humans, he mentioned about more work and lowering the food rations. He made the animals pamper him and abolished the song "Beasts of England". This helped to erase the evidence of the revolution in people's minds.
It signifies that Ahab sees himself as an equal and dependent part of a greater whole. Simply, he's lost part of himself trying to dominate it so now he is dependent upon it.
Macbeth has heard that his wife died but does not realize this as important and meaningless as life is only dust. Tomorrow is a phrase of beats of time that brings with it doom. The candle is maybe the imagery of a soul in which Macbeth's future is grim.
