What does the following quote mean? “[...] Unmannerly breeched with gore. Who could refrain/ That had a heart to love, and in that heart/ Courage to make ’s love known.”
In Act 2, Scene 3, Macduff discovers Duncan's dead body, and Macbeth and Lennox go into the bedchamber to see it for themselves. (Of course, Macbeth is acting because he killed Duncan himself a few hours earlier.) While Macbeth and Lennox are in the room, Macbeth kills the two chamberlains that he and Lady Macbeth framed for the murder. When Macduff asks him why he killed them, Macbeth says,
Who can be wise, amazed, temp'rate, and furious,
Loyal, and neutral, in a moment? No man.
Th' expedition of my violent love
Outrun the pauser, reason. (2.3.126-129)
In other words, he asks, who can think clearly when he feels all these big, conflicting feelings at once? He insists that his overwhelming love for Duncan outstripped his reason, and in saying that "No man" could love so much and not act as he did, Macbeth actually implies that he loved the king the most! He says that the murderers were
Steeped in the colors of their trade, their daggers
Unmannerly breeched with gore. Who could refrain
That had a heart to love, and in that heart
Courage to make 's love known?
The murderers were covered with blood, their daggers still coated with the gore of the murder. He asks, who -- if he really loved Duncan and had the courage to show it -- could see this sight and NOT kill the king's murderers? Again, he implies that he was one who most loved the king: pretty ironic since he was the real murderer.