Parāçara said:—Having heard the words of the cow-herd Nanda regarding the worship of Sakra, Dāmodara, to excite the anger of the lord of celestials, said—"We, father, are neither cultivators of the soil, nor merchants—we are sojourners in the forests and cows are our gods. There are four divisions of knowledge—logical, spiritual, practical, and political. Hear from me, what is the practical science.

In plain words: Parashara, the sage telling this story, says Krishna (here called Damodara) answered his foster-father Nanda in a way meant to make Indra angry. Krishna says: we are not farmers or traders, we live in the forests, and cows are our gods. He then begins to explain the practical knowledge of how people earn a living.