Luke 11:47-48

“Woe to you! for you build the tombs of the prophets, and your fathers killed them. So are you witnesses and consent to the works of your fathers, for they killed them, and you build their tombs.”

Furthermore they associated themselves with the slaughter of the prophets by building them great tombs without being overmuch concerned about what their fathers had done. They honoured the dead prophets, thereby acknowledging the truth of their words, but this did not make them follow the prophets' teaching in their daily lives or grieve over what their fathers had done, although they did piously say, ‘if we had been alive then we would not have done it' (Matthew 23:29). It was done in such a way that rather than being an act of repentance and mourning, it was almost an act of identification, as though it was something that could be expected. And by it they testified to the fact that they were sons of murderers. And they did it without turning a hair, while themselves being quite ready to do the same if the situation arose. (They would indeed do it with Jesus).