। ॥ ५ ॥
In plain words
This work follows scripture and does not walk ahead of it, so it takes up the four preliminaries. Whatever scripture itself points to as its own root is exactly what is set down here.
Close to the Sanskrit
Because of this (work's) conformity to the scripture, the fourfold set of preliminaries — that very one which has been declared the root of the scripture — is stated here.