Oh lord, won't you buy me a mercy dispense

The story:

Years and years I had asked myself what the heck couls it be: A mercy dispense. I knew what mercy was and I found out something about things that could be despensed. But how to dispense mercy? Who is a mercy dispenser? Is it a priest? A Guru?
I asked an american citizen what he thought. He did not understand and asked for a reason of my question. I began to sing Janis' chorus and the guy just went mad.
Mishearing and bad translation is doubling your embarrasment, I tell you boys and girls.