{Consent} (suneudokeite). Double compound (sun, eu,
doke(935c)), to think well along with others, to give full approval.
A late verb, several times in the N.T., in  Ac 8:1  of Saul's
consenting to and agreeing to Stephen's death. It is a somewhat
subtle, but just, argument made here. Outwardly the lawyers build
tombs for the prophets whom their fathers (forefathers) killed as
if they disapproved what their fathers did. But in reality they
neglect and oppose what the prophets teach just as their fathers
did. So they are "witnesses" (martures) against themselves ( Mt
23:31 ).