As they prepare for the attack, Malcolm's wishes that “chambers [bedrooms] will be safe\" in the coming future, referencing the location of King Duncan’s murder. The statement could also be emphasizing the fact that the play features sleeplessness. Macbeth and his wife have rarely had a good night’s sleep since taking over the country’s leadership. In response, Menteth assures Macbeth that they “doubt it nothing,” meaning the future king throne will be protected from those who wish to overthrow him.
Malcolm orders the soldiers to hew “down a bough,” using tree leaves for camouflage. Malcolm wants to use this trick to make it difficult for Macbeth and his men to determine the size of their troops. Although Malcolm does not realize this, his actions fulfill the prophecy concerning a moving forest toward Macbeth’s stronghold.
Only a few individuals remain at Macbeth’s side. These people are loyal to him out of constraint, not admiration. While Malcolm is working with a group of people that is utterly loyal to him, Macbeth’s heartlessness has hindered him from winning over servants and citizens alike. Siward notes that “thoughts speculative their unsure hopes relate / But certain issue strokes must arbitrate” (19-20). This statement means that time for action has come, and guesswork has ended. Malcolm and his group prepare for a battle that transforms Scotland.