The poem addresses the central teaching of the Buddha. The first five lines show that the so-called cyclic existence of births and deaths is an illusion from the viewpoint of ultimate truth. When in actuality there is no self or existence, there is no point talking about the eradication of self/existence. The allegory of ‘the page of sands’ stresses that the entire scenario of birth and death is just an illusory drama, because existence is anyway impossible as there is no solid ground to hold it.
The next five lines point out that everything that seems to have been happening in the beginningless history of the cosmos is just a causal process. Even this, he says, is not the truth. In his words: all this is an illusion, and that is the truth, and that is what the Buddha uttered.