In plain words
This they called the Kṛṣṇa Yajurveda. Then Yājñavalkya, recognising his fault well, for the wrong of having disobeyed his guru's command, gave up food and drink and went on with a hard worship of the sun. Holding that repentance itself is atonement, he went on undergoing this kind of atonement through repentance. After he had repented, the sun appeared before him, taking the form called Vāja: 'My son! What is past is past. Never again must you commit such faults. Treachery to the guru and treachery to God are very dangerous. So be careful.' Telling him this, the sun himself taught him the whole Veda again. Why did the sun appear in the form of Vāja? Yājñavalkya's forefathers had always made gifts of food. So that family came to be called Vājasa. It was because this name Vājasa had come to them that he took that form and taught him the Veda. This came to be called the Śukla Yajurveda. It also got another name, Vājasaskanda. It got yet another name too, Ādityaskanda. Because it was gained through worship of the sun, it got the name Ādityaskanda. Because he appeared in the form of Vāja and taught it, it got the name Vājasaskanda. In this way each one took on a form of its own. The Yajurveda came to be divided in two. Though the Vedas are four, because this Yajurveda was divided, they came to take shape as five. Ṛgveda, Yajurveda, Sāmaveda, Atharvaṇaveda: the four Vedas. Because in the Yajurveda there was a division in two, the Śukla Yajurveda and the Kṛṣṇa Yajurveda, they took shape as five Vedas. In those days, having won the sun's grace through worship of the sun, Yājñavalkya weighed, pondered and examined in every way that this was what mattered most in this world, and went on teaching the land duties of several kinds, the right duties for ordinary men. It was because my family made gifts of food in those days that today the sun himself came, taking the form of Vāja, was it not? That is why:
What gift is greater than the gift of food? What God is above mother and father? What character of Satya is above japa and tapas? What Dharma is greater than compassion? What gain, if you look, is above good company? What enmity is worse than anger? What disease is there for man worse than debt? What death is there on earth worse than ill fame? What wealth is there, at all times, greater than a good name? What ornament surpasses remembrance!