In plain words
For one who journeys in dakṣiṇāyana there is rebirth. For one who journeys in uttarāyaṇa there is no rebirth. He becomes whole and complete. In this same way, the five elements are the five feet of the sun. The twelve months are the twelve signs. Each month the sun enters one sign after another. Because he journeys in this way through the twelve signs in the twelve months, a kind of light takes shape within him. That too is a change that takes shape as seven colours. Each month has two fortnights. One is called śuklapakṣa, the second kṛṣṇapakṣa. What is this śuklapakṣa? What is this śuklapakṣa? In śuklapakṣa the moon stands facing the sun, so the full radiance of the sun falls upon the moon, and the moon too shines brilliantly with its sixteen digits. That is, because it is near prāṇa, the sixteen digits of the living being take on their full form, and it shines brilliantly under the name pūrṇimā. On the day of amāvāsyā the moon merges in the sun. Because it merges within the sun, the moon is not seen. So the waning of the moon's radiance from pūrṇimā onward is called kṛṣṇapakṣa, and because the moon's light grows little by little from amāvāsyā, this is called śuklapakṣa. Śuklapakṣa is prāṇa; kṛṣṇapakṣa is the living being. The blended form of this living being and prāṇa is itself the divine world. All these are simply the working of Prajāpati's resolve. Ekoʼhaṃ bahu syām. Though what is, is One alone, it keeps taking shape as many. How? When we plant a seed in the earth, it grows into a spreading tree, that tree bears thousands of fruits, within each fruit many seeds form, and again through those many seeds many trees come to be. What was planted was one seed; what makes it take shape as so many trees? That is ekoʼhaṃ bahu syām. One seed itself has gone on taking shape as many trees. One prāṇa itself has gone on dividing into many prāṇas. So creation has no fixed rule and no fixed meaning. In the beginning there were only these two: the living being and prāṇa. Through the union of these two alone it has taken shape as this whole world. This world has no end. It has no beginning either. Because people think of such a divine resolve, without beginning or end, as living beings, they believe these living beings have an end.