Listen, as the ancient divisions of time are revealed. The period known as twilight is counted as one hundred, and its portion is equal to itself. Within this vast cycle, four yugas unfold: Kṛta, Tretā, Dvāpara, and Kali. Let us now hear of their durations. The Kṛta Yuga spans forty thousand years, and likewise, other periods are reckoned in this way. The Tretā Yuga lasts for eighty thousand years, the Dvāpara for twenty thousand, and the Kali Yuga for sixty thousand years. Altogether, the yugas are calculated as six times sixty hundred thousand years. For each yuga, the twilight portion is twenty thousand years. When these yugas, with their twilight periods, are joined together, they form what is called a Manvantara. According to human reckoning, a Manvantara comprises thirty crores of years, and again, the twilight period is twenty thousand years, with a little more, never less. Thus, the span of a Manvantara, together with the yugas, has been described. Now, let us turn to what remains to be said about the Treta Yuga, as well as the Dvapara and Kali Yugas. These two yugas, which follow in order, have not yet been fully explained. At the dawn of the Treta Yuga, Manu and the seven sages were present. The union with wives, the Agnihotra sacrifice, and the collections of the Rig, Yajur, and Sama Vedas were established. Dharma, handed down through tradition, and the characteristics of proper conduct were set forth—through truthfulness, celibacy, study of the scriptures, and austerity. In the first Treta Yuga, for Manu and the seven sages, mantras such as the Taraka and others became manifest. Among all living beings, various perfections appeared. These mantras were revealed to them again through inspiration. The seven sages taught these mantras, and Manu proclaimed the traditional dharma. Because of the restriction of lifespan, these teachings would continue in the Dvapara Yugas. The divine ones, without beginning or end, were created by the Self-born. Although the Vedic doctrines hold the same meaning, they change according to each yuga. In these times, the Shudras performed service-sacrifices, while the best among the twice-born carried out recitation-sacrifices. They were active in rites, fruitful in offspring, prosperous, and happy. The Shudras followed the Vaishyas, and all were mutually devoted to one another. By intention of mind, by spoken word, and by their own actions, they possessed lifespan, intelligence, strength, beauty, health, and righteousness. Then, Brahmā established for them the system of varṇas and āśramas. Yet, through mutual conflict, these beings again approached Manu. Meditating, Manu begot two sons in Śatarūpā. From that time onward, kings arose, bearing the rod of punishment. By these kings, even hidden sins—those which human rulers cannot restrain—were addressed. The divisions of the varṇas were proclaimed in the Tretā age, and sacrifices were set in motion by the gods themselves, together with Viśvabhuj and the mighty Indra, king of the gods.