“That which is the finest essence, this whole world has it as its self. That is the truth. That is the self. You are that, Svetaketu.”

A father teaches his son with salt dissolved in water: taste any part and the salt is there, though the eye finds nothing. Like that, he says, the finest essence runs through the whole world, and you are that.

Three words carry the tradition's deepest idea. The full story, with the salt water and the banyan seed, is told on this site as The boy who thought he knew everything.