Question

Which lines in this excerpt from act III of Shakespeare’s Macbeth refer to Macbeth’s insecurity because of the threats to his kingship?

Answer 1

We have scotch'd the snake, not kill'd it;

She'll close, and be herself; whilst our poor malice

Remains in danger of her former tooth.

Answer 2

These are the lines from Macbeth's soliloquy,
"Upon my head they placed a fruitless crownAnd put a barren scepter in my grip,Thence to be wrenched with an unlineal hand,No son of mine succeeding. "

His kingship is in the threat of Banquo since he doesn't have a son to pass on his throne while Banquo has.