। ॥ १३ ॥
In plain words
Something in you tastes the faint sweetness of dreamless sleep and claims it: "I am happy." That claimant is the ahaṃkāra, the I-maker, going by the name ānandakośa, the sheath of bliss. How could that ever be the ātman?
Close to the Sanskrit
He who, by traces of pleasure found in deep sleep, conceives with conceit 'I am happy' — that ego, going by the name 'sheath of bliss', how could it be the Self?