Macbeth’s fatal flaw is his ambition. He was told of a
prediction by the witches that he would be king one day, and he cannot stop
thinking about it. When the king announces his son as his heir and not Macbeth,
he then kills the king and everyone else he thinks is against him.
It’s a public speaking because he will be speaking too audience.
I can provide you with a free copy of the book, if you'd like. Sadly, this cannot be answered directly.
Parallelism would be the most likely answer.
The sentences are structured similarly by "we have..." and contain similar messages