What does Banquo mean when he says "Were such things here as we do speak about? 85 Or have we eaten on the insane root That takes the reason prisoner"?

Shortly
after the Three Witches giveandtheir seemingly favorable prophecies, they vanish into thin air
and Banquo questions the authenticity of their predictions and the reality of the odd situation.
Banquo asks ,

"Were such things here as we do speak
about? Or have we eaten on the insane root That takes the reason prisoner" (Shakespeare,
1.3.83-85).

Banquo is essentially asking whether or not
the information andwere both real or were they simply hallucinating. The "insane root"
that Banquo refers to is more than likely hemlock or henbane, which are deadly herbs that cause
madness. Banquo is asking Macbeth if they accidentally ingested some poison that takes
"reason prisoner." He is saying that the poison would make them lose their minds to
the point that they can no longer think rationally, which is a reasonable question to ask after
witnessing the Three Witches vanish into thin air.