"It will have blood, they say; blood will have blood"

This quote is from William Shakespeare's play Macbeth and is spoken by Macbeth himself. It is an alerting to Macbeth that his actions will have repercussions which he will be held accountable for them. The quote is a metaphor for the concept that violence begets violence, and that if Macbeth dedicates a violent act, he will be consulted with violence in return. It is an alerting to Macbeth that he should think carefully before he acts, as his actions will have consequences that he may not be able to control. The quote is a suggestion that violence is a cycle that can be tough to break, which it can have far-reaching consequences. It is a warning to Macbeth that he must believe thoroughly before he acts, as his actions will have repercussions that he might not be able to manage.