Final answer:
The soliloquy including 'Unsex me here...' is from Lady Macbeth in Shakespeare's play 'Macbeth'.
Step-by-step explanation:
The soliloquy you are referring to is spoken by Lady Macbeth in Shakespeare's play Macbeth. The given lines are from Act 1, Scene 5, where Lady Macbeth is calling upon the spirits to make her cruel and unable to feel remorse so that she can go through with the murder of King Duncan without guilt. This soliloquy is significant as it shows Lady Macbeth's ambition and her desire to rid herself of any feminine weakness that could prevent her from committing regicide.