In Varaha Puranamnam it is stated that, relating to Vedadhyanam (i.e., study of Vedas), there are two approaches. The first is Brahma Sampradayam; the second is Aditya Sampradyam. In the same Puranam, it is stated that at the beginning of creation, in the very first Kalpa of the first Yugam, Lord Narayana killed the demon Shankasura, retrieved all the precious Vedas stolen by the demon and handed them over to Lord Brahma for safe keeping. Lord Brahma took this body of knowledge, which stipulates the do’s and don’ts for a human being to evolve rapidly, divided it into two parts, gave one part to Aditya (Sun God) and retained the other with himself. This knowledge, if properly studied and assimilated, will be of immense value to help all living creatures live in harmony.

Lord Brahma instructed sages such as Vasishta, and many other Rishis, on the part of the Vedas that were retained by him. At this stage, the body of knowledge was a homogenous whole. These were passed on by the sages to their children and students. This body of knowledge is referred to as ‘Brahma Sampradayam’.

Sage Yagyavalkya was the main custodian of the Aditya Sampradayam. He had originally studied Brahma Sampradayam from two gurus, Vidagdha Shakalya and Vaishampanya. Sage Vaishampanya and Sage Vidagha Shakalya, for some reasons (side story that is not germane to our current narration) instructed Sage Yagyavalya to relinquish all that he learnt from them. Thereafter, Sage Yagyavalkaya prayed to Sun God (the most visible form of God for earthly inhabitants) and embarked on intense austerities. When he relinquished all that he learnt from his two gurus, all that he was left with was the Gayatri Mantra (a prayer to Sun God), which he learnt from his father. This Mantra has 24 aksharas (fundamental characters in Sanskrit language). He performed hundred thousand chantings of Gayatri Mantra for each of these characters, thereby earning the grace of Sun God, who instructed the Sage on the Aditya Sampradayam. This part that he learnt from Sun God had the entirety of the Vedas, just as did Brahma Sampradayam. This Sage then instructed his disciples starting from Sage Kanva and many others (their progeny as well as many other disciples), on the Aditya Sampradayam. All this is corroborated by Varaha Puranam, which is an authoritative text.

The Brahma Sampradayam was divided into four parts by Sage Vedavyasa, namely Rig, Yajur, Sama, and Atharva, to enable suitable performance of various Yagnas. For the performance of any major Yagna, it is essential to have the following four roles, which were taken by Rutviks (officiating priests), namely, Adhvaryu, Hota, Udghaataa, and Brahma. In the Yagna, the mantras inchanted by Adhvaryu were compiled to form Yajur Veda. In a similar manner, the mantras inchanted by Hota, Udghaataa, and Brahma were compiled to form respectively Rig, Sama and Atharveda. These four vedas were further subdivided into shakhas. Over time, Rig Veda was divided into 21 shakhas for ease of learning by students. The Yajur Veda that was part of Brahma Sampradayam evolved into Krishna Yajur Veda and was similarly divided into 86 shakhas. Sama Veda likewise had 1000 shakhas.

Atharva Veda had nine shakhas. The Aditya Sampradayam did not have division into Shakhas. However, the four Vedas (Rig, Yajur, Sama and Atharva) are embedded in the Aditya Sampradayam as well. The part of Yajur Veda that emanated from Aditya Sampradayam is termed, ‘Shukla Yajur Veda.’ The above has been narrated in Charana Vyuhadi grantha (text).

On a different note, Sage Vedavyasa, who classified the Vedak, taught the four Vedas to Sage Vaishampayana. Sage Vaishampayana had twenty- seven disciples. Sage Vaishmpayana taught Rig Veda to one of his disciples at a place called Sindhu (now in Pakistan). The Shukla Yajur Veda was taught by Sage Vaishampayan to Sage Yagnavalkya in Kurukshetra. Sage Yagnavalkya was the foremost among the 27 disciples of Sage Vaishampayana.