Fair is foul, and foul is fair Hover through the fog and filthy air.
.... He (Macbeth) unseam'd him(Macdonwald) from the nave to the chops.
Hail to thee, Thane of Cawdor
All hail Macbeth! that shalt be king hereafter
Thou shalt get kings, though thou be none
The very first scene starts with three witches in the thunderstorm. Shakespeare uses the phrase above in scene 1 line 11 saying that things considered good is bad and things considered bad is actually good, meaning that there are always reasons behind it. This indicates that the three witches are predicting what will happen in the future and knows something horrible will happen to the characters.
It istoo full o' the milk of human kindness to catch the nearest way
The captain who was in the war tells King Duncan and his sons that Macbeth chopped his way through to Macdonwald, split him from his navel to his jawbone and stuck his head on their castle walls. This reveals Macbeth's behavior that he is a very skilled man and very brave compared to other men since I believe not a lot of people are able to chop someone's head and jawbone.
O, never Shall sun that morrow see! Your face, my thane, is as a book where men May read strange matters. To beguile the time, 55Look like the time. Bear welcome in your eye, Your hand, your tongue. Look like th' innocent flower, But be the serpent under ’t. He that’s coming Must be provided for; and you shall put This night’s great business into my dispatch, 60Which shall to all our nights and days to come Give solely sovereign sway and masterdom.
Macbeth and Banquo meet three witches and meeting up with them completely changed their lives since witches were saying what will happen to them in the future. They said that Macbeth will be the Thane of Cawdor and will be a King of Scotland. They also said that Banquo's children will be kings in the future. As soon as witches disappeared, Ross came up with a great news saying that Macbeth is now a Thane of Cawdor. Therefore, I can say that witches knows what will happen in the future.
First, as I am his kinsman and his subject.
then, as his host, Who should against his murderer shut the door, Not bear the knife myself.
Macbeth's letter to Lady Macbeth was about what witches said to him and also told her that he became the new Thane of Cawdor just like what witches told him. From this, I can infer that they are very close to each other as they share secrets and are ambitious. Lady Macbeth said Macbeth is "too full o' the milk of human kindness to catch the nearest way", this indicates that Macbeth is too kind to kill King Duncan in order to be a King of Scotland.
Lady Macbeth's phrase above reveals her personality and behavior towards Macbeth. I can infer that she is very manipulative and cruel as She wants Macbeth to look innocent on the outside (like a flower) but be harsh and murder King Duncan when the time comes. She behaves like a boss towards Macbeth which shows that she has more power over him. Since she wants to get rid of anything that gets in the way of Macbeth's ambitions, she continued to manipulate him until he becomes the king of Scotland.
Macbeth doesn't want to kill Duncan for two reasons as you can see above and only has one reason to kill the King, his own ambition. Even though he is considered as a brave and skilled man, he cannot murder Duncan since he was the one to host him to the new Thane of Cawdor, which shows that he is very loyal to Duncan. However, because he got manipulated by Lady Macbeth and not powerful enough to go against her, he decided to murder him and out his false face.