Even though you know, you don't understand. I give this as homework to everybody. All the people who practiced at the Zen center already understand. Coming empty handed, going empty handed, that is human. Where we come from, we don't know.
Life is like a floating cloud which appears, death is like a floating cloud which disappears.
In empty space there is no absolute truth. In time and space, truth appears and disappears. The cloud that goes back and forth has no substance. If you try to hit empty space, nothing happens. There is one thing which is always clear, not dependent on life and death.