। ॥ ४७८ ॥
In plain words
The sky is nothing the eye ever actually reaches — no sense touches it — and still people who have not looked call it blue, and give it a dome besides. That is exactly what happens with this Self. The mind slips, and onto the ātman too they lay whatever they please.
Close to the Sanskrit
Just as the unknowing superimpose blueness and the like upon the sky, which is not an object of sight or of the other senses, so too, precisely, do they superimpose upon this Self as well, out of an error of the mind.