How we cite our quotes:
MACBETH From this moment The very firstlings of my heart shall be The firstlings of my hand. And even now, To crown my thoughts with acts, be it thought and done: The castle of Macduff I will surprise, Seize upon Fife, give to the edge o' the sword His wife, his babes, and all unfortunate souls That trace him in his line. (4.1.16)
Like potato chips, you can't have just one murder. All Macbeth wanted to do was kill the king, and now he's off to slaughter some innocent babes. (Pro tip: just don't buy the bag of potato chips in the first place.)
Let us seek out some desolate shade and there
Weep our sad bosoms empty.
Let us rather
Hold fast the mortal sword, and like good men
Bestride our downfall'n birthdom. Each new morn
New widows howl, new orphans cry, new sorrows
Strike heaven on the face, that it resounds
As if it felt with Scotland and yell'd out
Like syllable of dolor. (4.3.1)
Malcolm wants to take a second to weep about his murdered father, but Macduff is ready to get some avenging done. Notice how he talks about it, though. He doesn't say, "Let's go kill us some men"; he says, "Let's go make some widows and orphans." Is this just a poetic way of saying it, or is this Shakespeare slyly reminding us that violence has consequences?
Had he his hurts before?
Ay, on the front.
Why then, God's soldier be he!
Had I as many sons as I have hairs,
I would not wish them to a fairer death:
And so, his knell is knoll'd. (5.11.2)
If your son has to die in battle, you at least want him to die with his wounds "before," or in front, facing the enemy. For Siward, this is the best possible way for a young man to die. (No word about living to a ripe old age, of course.)