सहस्रयुगपर्यन्तमहर्यद् ब्रह्मणो विदुः | रात्रिं युगसहस्रान्तां तेऽहोरात्रविदो जनाः ||८-१७||
sahasrayugaparyantamaharyad brahmaṇo viduḥ . rātriṃ yugasahasrāntāṃ te.ahorātravido janāḥ ||8-17||
Chapter 8 · Verse 17
Akshara Brahma Yoga
अक्षरब्रह्मयोग
In plain words
Day means evolution or projection or manifestation of the universe. Night means involution of the universe or Pralaya. The worlds are limited or conditioned in time.
Translation
8.17 Those poeple who are knowers of what day and night are, know the day of Brahma which ends in a thousand yugas [The four yugas (in the human worlds), viz Satya, Treta, Dwapara, and Kali are made up of 4,320,000 years. This period multiplied by a thousand constitutes one day of Brahma. His night also extends over an eal period. See M.S. and V.S.A.], and His night which ends in a thousand yugas. 8.17 Those people who know the day of Brahma which is of a duration of a thousand Yugas (ages) and the night which is also of a thousand Yugas duration, they know day and night. 8.17 Viduh, they know; that ahah, day; brahmanah, of Brahma, of Prajapati, of Virat; yat, which; sahasra-yuga-paryantam, ends in a thousand yugas; and also the ratirm, night; yuga-sahasra-antam, which ends in a thousand yugas, having the same duration as the day. Who knows (these)? In reply the Lord says: Te, they; janah, poeple; ahoratra-vidah, who are the knowers of what day and night are, i.e. the people who know the measurement of time. Since the worlds are thus delimited by time, therefore they are subject to return. What happens during the day and the night of Prajapati is being stated:
Meaning
Day means evolution or projection or manifestation of the universe. Night means involution of the universe or Pralaya. The worlds are limited or conditioned in time. Therefore they return again. The world of Brahma (Brahmaloka or Sattyaloka) is also transient although it lasts for a thousand ages. When the four great Yugas have gone round a thousan times it make a daytime of Brahma and when an eal number of Yugas pass again it makes a night. Those who can see and live through the day and night of Brahma can really know what is a day and what is a night. The Suryasiddhanta speaks of the same division of time. According to it YearsKaliyuga (with its Sandhya andSandhyamsa) consists of 432 000Dvapara Yuga (do) 864 000Tretayuga (do) 1 296 000Kritayuga (do) 1 728 000Thus a Mahayuga consisting ofthese four Yugas comprises 4 320 00071 such Mahayugas with an additionalSandhya at the close of 1 728 000years make one Manvantara of 308 448 00014 such Manvantaras with anotherSandhya at the close of 1 728 000years constitute one Kalpa of 4 320 000 000Two Kalpas make a day and nightof Brahma of 8 640 000 000360 such days and nights make oneyear of Brahma consisting of 3 110 400 000 000100 such years constituteHis lifetime of 311 040 000 000 000The world is absorbed in the Avyakta or the Unmanifested or Mulaprakriti during the cosmic Pralaya (involution of the world). Just as the tree remains in a latent state in the seed so also this whole universe remains in a latent state in a seedform in the Mulaprakriti during Pralaya. This is the night of Brahma. This is the cosmic night. Again the world is projected at the beginning of the Mahakalpa (evolution). There comes the cosmic dawn or cosmic day. This eternal rhythm of cosmic day and night (evolution and involution) is kept up in the macrocosm. Nothing that comes under this everrevolving wheel of cosmic day and night lasts for ever. That is the reason why the seers of the Upanishads the sages of yore lived in the transcendental Supreme being the imperishable Self the indestructible Purusha the supreme goal of life the highest end of man which is beyond the cosmic day and night. Just as the seeds that are fried can hardly germinate so also those who have attained to the imperishable Brahman the Absolute the Eternal cannot return to this world of sorrow pain and misery. They know neither day nor night. They are one with Existence Absolute. The manifested and the unmanifested dwell in Brahman. Brahman is beyond the manifested and the unmanifested. When the world and the body are destroyed Brahman is not destroyed. The waves come out and subside but the ocean remains unaffected. So also the worlds come and subside but Brahman the source of everything the source of Mulaprakriti ever remains unaffected. Just as ornaments come out of gold and then go back to gold when they are melted so also all the worlds come out of Brahman and go back to Brahman. Gold is in no way affected by the various forms such as earning bracelets anklets etc. that have been made of it. Even so Brahman is not in the least affected by the projection and destruction (dissolution) of the worlds and the bodies of beings. It remains always as It is.
Word by word
सहस्रयुगपर्यन्तम् ending in a thousand Yugas (ages) अहः day यत् which ब्रह्मणः of Brahma विदुः know रात्रिम् the night युगसहस्रान्ताम् ending in a thousand Yugas (ages) ते they अहोरात्रविदः knowers of day and night जनाः people.