The only way that we ever understand anything is by comparing it with something or contrasting it with something. That's the only way we ever understand anything - comparison, contrast. Without all those tens of thousands of lambs on the altar of Israel, we could never understand what Jesus came to do. In our own experience an animal takes the place of a man. We take an animal.
Some people are opposed to that.
They are not thinking it through. We don't favor cruelty to animals, but on the other hand, we must test our drugs and we must test our procedures. The answer's obvious. It would be better for 10,000 mice to have cancer if a cure for cancer for people could thereby be found. So, for an animal to take the place of a man is not only a part of Israel's experience, but it's a part of our experience, and not just in the world of research.