The subtle body itself is an obstacle that is tied to limited intelligence and the ego. The enslaved person has experiences that are tied to his beliefs and to the idea that he has of his body, and in this very way perpetuates the tie.

During interviews or questions, those who believe in certain things say that they are sure it is this way because they have experienced it. Not for a second do they see that their experience is caused by their belief. This is obviously something very subtle. This stanza is a little dig at the intentions of traditional yoga, where there is much discussion on different forms of the body. Here, it is simply being said that when one believes that subtle body exists, one will have an experience of the subtle body; when one believs that a bicycle created the universe, one will have mystical dreams about the bicycle that created the universe and the stigmata of a cyclist. This is therefore a key for taking inventory of our beliefs and for seeing how those experiences that confirm certain beliefs are tied to our certainities. This is something extraordinary - it deconditions us from certainty and leads us into this very Tantric domain where nothing is affirmed and nothing is denied. Then we save an extraordinary amount of energy that we can use in the real work. We no longer have this necessity to cling to beliefs and dogmas, nor to deny them: We are free. We can simply enter into the reality of the body, thoughts, sensations.
Now, each time we have an experience that seems to confirm a notion, even an uncertain one, we will continue to cling to it, but with a little smile on our lips - because we know that we are having an experience of what we believe. It is a subtle observation, as we are used to reasoning in the other direction, where we live our experiences as proof of our beliefs. It is important to do this with our little daliy beliefs as well. For tantrikas, this is play. We construct something, then take apart the thing constructed, and this leads us to spatiality.
We never have the idea that a construction is made to be definitive; rather, we see it as a cycle of appearances and disappearances. We create a vision, and we reabsorb it by attention to the vacuity that disappears in plenitude and joy. When we do lineage yoga, it is exactly the same. We create something from start to finish, we put it into vibration, and then we allow to unmake itself in light, in vibrating darkness. At the end of practice, we get a taste of space.