astrophysics - How can Quasars emit anything if they're black holes?

We've heard it many times, nothing can escape the gravity of a black hole, even light once it's past the event horizon. If this is true, how can a black hole emit anything? Quasars are massive black holes that have consumed enormous amounts of matter and energy, and then blasted it back out into the universe. How is this possible? Time stands still in a black hole, that in itself should stop anything from moving.