A Couple of Random Questions???

Matthew 27:50-53
And when Jesus had cried out again in a loud voice, he gave up his spirit. At that moment the curtain of the temple was torn in two from top to bottom. The earth shook and the rocks split. The tombs broke open and the bodies of many holy people who had died were raised to life. They came out of the tombs, and after Jesus' resurrection they went into the holy city and appeared to many people.

I've often wondered why I've never heard a sermon on these particular scriptures...

And what were these people who were raised from death doing for the 3 days before Jesus was resurrected?

This part of Jesus' death on the cross always has intrigued me...well really the whole raising from the dead thing has (regular people not Jesus)...Here is my question, trivial as it may be but what happened to these people who were raised from the dead? Did they die again eventually... were they raised from the dead to bring glory to God then to die again at a later date?
Hmmmmmmm.........