Mat 27:52 And the graves were opened: and many bodies of the saints that had slept arose,
Mat 27:53 And coming out of the tombs after his resurrection, came into the holy city and appeared to many.
If the people in Jeruselem were not convinced by the protracted solar eclipse, the must have been overwhelmed by the unusual visitation.
Imagine David, Moses and Isiah mingling with the people, telling them about the wonderful event that has just occurred. It always puzzled me why Chritianity had such hard time getting off the ground with such a spectacular opening ceremony and why anyone believed the "stolen body" crap that was propagated by Caiaphas and his cronies.
Again we see that the imagination of the Gospel writers knew no bounds.