What does it mean to say "from near to far, from big to small, from death to life, from top to bottom, from virtual to real"?

This is the so-called "heroes don't suffer immediate losses" strategy adopted by the underground party in the struggle against the enemy.

In the process of fighting the enemy, once the underground party is arrested, it is often tortured. In this case, we should adopt the strategy of "talking far but not near, talking big but not small, talking dead but not alive, talking up but not down, talking empty but not telling the truth", that is, telling what the enemy already knows or "what everyone knows" and not telling secrets that the enemy does not know. The dead say (because the dead can't prove it) that the living don't say it, and even deliberately give the enemy some false information (false information) to hide the true information ... In this way, the enemy can neither gain substantial gains, but also save himself (less suffering from the same flesh and blood).