What are illusions? Illusions are unreal, like a magician's tricks. The magician recites a mantra and a lotus flower suddenly appears in the water. Perhaps there were no fish in the water to begin with, but after he recites a mantra, fish appear. You may see what appears to be fire, but suddenly the magician pulls a lotus flower from the flames. He seems to have such spiritual penetrations and wonderful abilities, but actually they are all tricks of illusion. They have no reality. Although they seem to be there for real, if you investigate further, you find that they are not really there. Children and foolish people see the fish in the water, and do not realize that it is fake fish. They do not know that the lotus in the fire is just a trick of illusion. However, adults recognize that these are magicians' tricks and are not for real. Although adults know this, children do not.
When you understand the Buddhadharma you know that everything is false and illusory. The world is also false and illusory, realized from a conflux of conditions. When you do not understand the Buddhadharma, you are like a child or a fool. People who do not understand the Buddhadharma are really children. This is not to belittle them: it is a simple fact. They think that everything is real: being wealthy is real and being an official is real. In actuality, everything is one. A person is the same whether he is rich or impoverished. If you understand that everything is false and illusory, then you cannot be confused by anything. You will not become attached to unreal states.
Bubbles are also basically unreal, and quickly disappear to show their emptiness.
Shadows follow people around. When there is form, then there is a shadow. The form is an actual substance, the shadow is unreal. If explained in more depth, even form itself is unreal and does not actually exist. If you do not believe that, then just continue to be attached to your body, take care of it, and see whether or not it dies.
to be continued