Although one may say, “This is the light of the lamp,” there are innumerable rays of light being created, transformed and destroyed at every moment; and although one may speak of the water of the river, there is an ever-new supply of different water molecules passing by. Similarly, when one meets a young child, one accepts that particular transitory phase of the body as the actual identity of the person, considering him to be a child. One also considers an old body to be an old person. In fact, however, the material body of a human being, just like the waves of a river or the radiation of a lamp, is merely a transformation of the three modes of material nature, the potency of the Supreme Lord. The real identity of a person is spirit soul, part and parcel of Lord Kṛṣṇa, but as Lord Kṛṣṇa proves in this verse, a conditioned soul is incapable of observing or understanding the subtle movements of time. With the gross vision of material consciousness one cannot ascertain the subtle segments of material manifestation, which are impelled by the Lord Himself as time. The word mṛṣāyuṣām in this verse indicates those who are uselessly wasting their time in ignorance without understanding the instructions of the Lord. Such persons gullibly accept any particular phase of the body to be the actual identity of the spirit soul within the body. Because the spirit soul is not subject to material transformation, when he engages himself in the eternal variegated pleasure of Kṛṣṇa consciousness, loving service to the Supreme Lord, he will experience no further ignorance and suffering.