What is happening in the quote They hailed him father to a line of kings Upon my head they placed fruitless crown and put barren scepter grip Macbeth?

The quote, "They hailed him father to a line of kings/Upon my head they placed fruitless crown and put barren scepter in my gripe," reveals Macbeth's deep-seated ambition and insatiable thirst for power. This statement comes after the witches' prophecies, which foretold that Macbeth would become the Thane of Cawdor and eventually the King of Scotland. Despite already being a respected and accomplished warrior, Macbeth is unable to resist the temptation of the crown and embarks on a ruthless path of violence and manipulation to seize power. The "fruitless crown" and "barren scepter" symbolize the hollowness and emptiness of his kingship, as he sacrifices his moral integrity and true self in pursuit of the crown. These words highlight the tragic flaw in Macbeth's character and foreshadow the disastrous consequences of his actions.