Because he is an idiot.
Jujnio
When the witches proclaim his prophecies.
Because they do things in threes. They had three prophecies for Macbeth and now they have three for Banquo.
The witches only gave Macbeth prophecies. It was his decision to do so after Lady Macbeth persuaded him. Although the witches' intentions was probably to cause this murder, the witches did not make Macbeth muder Duncan.
They have insight into the future, which is why they can make prophecies.
Not long after telling Macbeth he'll become Thane of Cawdor, he is given the title. In the second set of prophecies, the witches seem to know Macbeth's castle will be stormed and how it will be taken over.
When the witches proclaim his prophecies.
In Shakespeare's play "Macbeth," the three witches are the ones who make the prophecies about Macbeth becoming king. In addition to Lady Macbeth, Macbeth himself learns about the prophecies from the witches and later seeks them out for more information. Ultimately, Macbeth's actions are driven by his desire to fulfill the prophecies and maintain his position as king.
Macbeth is startled when the witches give him their prophecies of his future. However, they did not tell him how to accomplish these prophecies, so he madly and erratically takes things into his own hands with the help of Lady Macbeth.
Macbeth
Because they do things in threes. They had three prophecies for Macbeth and now they have three for Banquo.
The witches only gave Macbeth prophecies. It was his decision to do so after Lady Macbeth persuaded him. Although the witches' intentions was probably to cause this murder, the witches did not make Macbeth muder Duncan.
They have insight into the future, which is why they can make prophecies.
beacuse he has haith in the witches' prophecies
Not long after telling Macbeth he'll become Thane of Cawdor, he is given the title. In the second set of prophecies, the witches seem to know Macbeth's castle will be stormed and how it will be taken over.
Macbeth killed King Duncan after hearing the witches' prophecies and being urged on by his wife, Lady Macbeth
The three witches predict that Macbeth will become the Thane of Cawdor and then the King of Scotland. They also predict that Banquo's descendants will inherit the throne, sparking Macbeth's ambition and actions to make the prophecies come true.
Macbeth kills King Duncan because he is manipulated and influenced by the witches' prophecies, particularly the prediction that he will become king. While the witches' predictions play a role in triggering Macbeth's ambition, ultimately it is his own choices and actions that lead to Duncan's murder.