Watch Lady Macbeth exhort Macbeth to murder Duncan in William Shakespeare's tragedy Macbeth

LADY MACBETH: 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, had I so sworn as you
Have done to this.

MACBETH: If we should fail?

LADY MACBETH: We fail?
But screw your courage to the stickingplace,
And we'll not fail.