(3.4.123)"It will have blood, they say, blood will have blood. Stones have been known to move and trees to speak. Augurs understood relations have by maggot-pies and coughs and rooks brought forth the secret’s man of blood." This is foreshadowing the fact that Duncun, Banquo and others shall be dispatched. The bloody hand represents the foreshadowing terror that will occur.
The Morrigan is a Celtic goddess of battle, strife, and sovereignty. She sometimes appears in the form of a crow, flying above the warriors, and in the Ulster cycle she also takes the forms of an eel, a wolf and a cow.