There is an interesting account about Sage Yajnavalkya and about the Yajur Veda, said Velukkudi Krishnan, in a discourse.
Sage Vaisampayana had many pupils, of whom Yajnavalkya was one. Sage Vaisampayana was no ordinary teacher. He was himself the pupil of the great Sage Vyasa. One day Yajnavalkya had a dispute with Vaisampayana. Yajnavalkya spoke disparagingly of Vaisampayana’s other disciples and claimed that he was the knowledgeable one among Vaisampayana’s disciples.
Yajnavalkya’s argumentative attitude angered his teacher. So Vaisampayana said to Yajnavalkya, “Throw up all the Vedas that I have taught you.” Yajnavalkya accordingly threw up what he had learnt. However, in view of the sacredness of the Vedas, Vaisampayana was anxious that they should not hit the ground. So he ordered his other disciples to take the form of partridges (tittiri). These pupils in the form of the tittiri birds swallowed up the Vedas as they came out of Yajnavalkya’s mouth. Because the tittiri birds prevented what Yajnavalkya threw up from falling to the ground, this portion acquired the name Taittiriya.
Yajnavalkya then distanced himself from Vaisampayana, and decided that he would learn something other than what he had learnt so far. He worshipped the Sun God, and the Sun God appeared before the sage. What Yajnavalkya learnt as result of his penance came to be known as Shukla Yajur Veda. What had been thrown up by Yajnavalkya was the Krishna Yajur Veda. The Taittiriya Upanishad has a section titled Sikshavalli. The Sikshavalli contains invaluable advice which an Acharya gives to his student. It is advice that should be borne in mind at all times, and is valid at all times.