Duke Zhou dreamed that acquaintances jumped down from the slope to save injured relatives and vomited infinite blood. What do you mean?

Your statement is not very clear. According to my understanding, vomiting blood means "painstaking efforts", that is, a lot of painstaking efforts have been made. Vomiting blood to save people from harm means that you have paid a lot for someone, and you have lost something important (such as health, time, etc.). You should also know something about dream interpretation, such as the mood in the dream, your own understanding of the dream, what happened before the dream and so on. This can only be explained here. If you need specific explanation, please explain the situation in detail.