"First, as I am his kinsman and his subject, Strong both against the deed; then as his host, who should against his murderer shut the door, not bear the knife myself.
Macbeth backs out
We will proceed no further in this business.
Know you not he has?
Prithee, peace. I dare do all that will become a man.
Was the hope drunk wherein you dressed yourself? Hath it slept since? And it wakes now , to look so green and pale at what it did so freely?
Macbeth is conflicted on whether he should go through with murderering the king. He's afraid of the consequences that come with killing the king. Killing king Duncan in his home is also the worst thing you could do as a host. Your guests should feel safe in your home.
The nursing baby
When you durst do it, then you were a man; And to be more than what you were, you would be so much more the man.
Lady Macbeth asks why Macbeth isn't talking to the king. He comes out and tells her he is not going to kill the king and that he's done nothing but treat Macbeth well.
If we should fail-
We fail? But screw your courage to the sticking place and we'll not fail.
Lady Macbeth is furious with Macbeth. She asks him if he was drunk when he said yes to killing the king. She basically says that Macbeth is just all talk.
I am settled and bend up each corporal agent to this terrible feat.
Lady Macbeth claims that when he said he would kill the king he was a man and if actually were to go through with it he would be even more of a man. She also gets somewhat dark and gives a visual of her nursing a baby and throwing it on the ground if she had been told to do so. She was trying to say that if she said she would do something, as messed up the situation, she would keep her word.
I would, while it was smiling in my face, have plucked my nipple from its boneless gums and dashed the brains out, had I so sworn as you have done to this.
Macbeth is eventually convinced but is anxious about them failing and getting caught because that would be the end to everything. Lady Macbeth explains how she'll take care of it and they just need to get the guards drunk so they can put the blame on them.
Macbeth has agreed to the plan. They agree that they need to make sure their faces don't give away anything and that when the murder does take place they show immense amounts of grief so they aren't suspected.
Who dares receive it other, as we shall make our griefs and clamor roar upon his death?