Final answer:
The purpose of Lennox's speech is to convey important information to other characters.
Step-by-step explanation:
The purpose of Lennox's speech in Scene VI of the play is to convey important information to other characters. Lennox's speech provides important details and insights about the events unfolding in the play, specifically about the murder of King Duncan and the suspicions surrounding Macbeth. It helps to advance the plot and bring clarity to the other characters in the scene.