avyakta-jīva-mahatām api kālam āhuḥ
so ’yaṁ tri-ṇābhir akhilāpacaye pravṛttaḥ
kālo gabhīra-raya uttama-pūruṣas tvam
The word gabhīra-rayaḥ, or “imperceptible speed and power,” is significant. We observe that by the laws of nature all material things, including our own bodies, gradually disintegrate. Although we can perceive the long-term results of this aging process, we cannot experience the process itself. For example, no one can feel how his hair or fingernails are growing. We perceive the cumulative result of their growth, but from moment to moment we cannot experience it. Similarly, a house gradually decays until it is demolished. From moment to moment we cannot perceive exactly how this is happening, but in the course of longer intervals of time we can actually see the deterioration of the house. In other words, we can experience the results or manifestations of aging and deterioration, but as it is taking place the process itself is imperceptible. This is the wonderful potency of the Supreme Personality of Godhead in His form of time.
The word tri-ṇābhiḥ indicates that according to astrological calculation of the sun’s movements, the year can be divided into three sections: those represented by Aries, Taurus, Gemini and Cancer; Leo, Virgo, Libra and Scorpio; and Sagittarius, Capricorn, Aquarius and Pisces.
The word uttama-pūruṣa, or puruṣottama, is explained in Bhagavad-gītā (15.18):
yasmāt kṣaram atīto ’ham
akṣarād api cottamaḥ
ato ’smi loke vede ca
“Because I am transcendental, beyond both the fallible and the infallible, and because I am the greatest, I am celebrated both in the world and in the Vedas as that Supreme Person.”