Not thinking about anything is Zen. Once you know this, walking, sitting, or lying down, everything you do is Zen.
Once you see your nature, sex is basically immaterial.
People who don't see their own nature and imagine they can practice thoughtlessness all the time are liars and fools.
But while success and failure depend on conditions, the mind neither waxes nor wanes.
I never lost or fail, not yet conquered. If I fall seven times, I get up eight
Externally keep yourself away from all relationships, and internally have no pantings in your heart; when your mind is like unto a straight-standing wall, you may enter into the Path.