I have given suck, and know
How tender ‘tis to love the babe that milks me
I would, while it was smiling in my face
Have plucked my nipple from his boneless gums
And dashed the brains out (1.7)

Lady Macbeth speaks these lines when she is trying to shame Macbeth for questioning their plan. She uses the image of a child to make a graphic statement about her own ambition and capacity for violence. By describing herself as a tender and loving mother who nonetheless would have killed her own child before she would abort a plan to seize power, Lady Macbeth disrupts the typical idea of what women and mothers are like. She uses this image to make her husband that he is being unmanly by doubting their scheme.

For Banquo’s issue have I filed my mind
For them the gracious Duncan have I murdered (3.1)

Macbeth speaks these lines when he is brooding about his worries that, as the witches have prophesied, Banquo’s heirs will someday gain control of the Scottish crown. Macbeth reveals that he feels guilty about the terrible things he has done, and that he is wondering if these acts were worthwhile. Even though he currently holds power, Macbeth lacks children who will hold power after him and this makes him fear that he has committed terrible deeds for no reason. These lines speak to a strong interest in stable succession, which was a key political issue in Shakespeare’s time.

What, all my pretty chickens and their dam
At one fell swoop (4.3)

Macduff speaks these tragic lines upon learning that his wife and children have been murdered. The affectionate imagery he uses to describe them shows how even though he is a strong and powerful warrior, he is also a loving husband and father. The line conveys the sense of overwhelming loss he feels when he hears that he has lost his entire family at the same time. The sense of immense grief sets the stage for his desire to avenge them by eventually killing Macbeth.

Had I as many sons as I have hairs
I would not wish them a fairer death (5.11)

Siward, a minor character, speaks these lines at the end of the play when he learns that his son has been killed in battle. Even though he is grief-stricken, he is proud that his son died a brave and honorable death. The line shows how important honor and valor are to characters in the play, and also how important it was for Macbeth to be defeated. A father can consider it worthwhile to have lost his child if it means knowing that Macbeth no longer occupies the throne.