"Be lion-mettled, proud, and take no care who chafes, who frets, or where conspires are Macbeth shall never vanquished be until Great Birnam Wood to high Dunsinane Hill Shall come against him"
The witches are making a poison potion in the cauldron to cause trouble and to please Hecate. As they are doing this Macbeth appears. Macbeth has questions he wants answers to.
How now, you secret, black, and midnight hags? What is ’t you do?
Double, double toil and trouble, fire burn, and cauldron bubble
The witches summon the first apparition, it appears to be looking like a head with an armored helmet which tells Macbeth to beware with Macduff.
Whate'er thou art, for thy good caution, thanks
come high or low; Thyself and office deftly show!
Macbeth! Macbeth! Macbeth! BEWARE of Macduff
Thunder: FIRST APPARITION
"Then live, Macduff. what need i fear of thee? but yet i'll make assurance double sure and take bond of fate thou shalt not live"
The witches summon the second apparition which appears to look like a bloody child. The child tells him to be violent, bold and firm because no one can harm him.
"Here's another more potent than the first"
"Be bloody, bold and resolute Laugh to scorn the power of no man, for none of women shall harm Macbeth"
Thunder: SECOND APPARITION
The witches summon the third apparition. It appears in a form of a child with a crown on his head and a tree in his hand. the child says that Macbeth will never be defeated until Birnam wood marches to fight you at Dunsinane Hill
"That will never be"
Thunder: THIRD APPARITION
Macbeth then asks a question about Banquo's sons. The witches tell Macbeth to not ask any more questions, but he demands for a answer. The witches show Macbeth the fourth apparition. Macbeth then sees a line of eight kings, the last king holds a mirror in his hand, followed by the ghost of Banquo.
Seek to know no more
Shall Banquo's issue ever Reign in this kingdom
The witches advise Macbeth "Seek to know no more" in an attempt to manipulate him and lure him to commit further crimes. The apparitions alter Macbeth's way of thinking to get him to murder Macduff.