Instead of just ordering the assassins/murderers to kill Banquo, Macbeth converses with them at length. Why? Act 3 sc i

Because the men aren't seasoned assasins, but rather poor men desperate for money, Macbeth takes extra time to convince them that they are justified in desiring Banquo's death as much as he does, as Banquo, according to Macbeth, is responsible for their poverty.