Charles Spurgeon Commentary Luke 11:47-48

"Woe unto you! for ye build the tombs of the prophets, and your fathers killed them. So ye are witnesses and consent unto the works of your fathers: for they killed them, and ye build [their tombs]." — Luke 11:47-48 (ASV)

They pretended to have such regard for the holy men of the past that, being unable to honor them in person, they would set up monuments to their memory and adorn their resting places with tokens of respect. Out of their own mouth our Lord condemned these hypocrites: Truly ye bear witness that ye allow the deeds of your fathers.

In effect, Jesus said to them, "You confess that you are the sons of the murderers of the prophets. That admission carries with it far more than you imagine. You are their sons, not only by birth, but also by resemblance; you are veritable children of those who killed the prophets. If you had lived in their day, you would have committed the crimes you pretend to condemn."