The Introduction of Ajjhāyaka

Then some of these beings thought: Evil things have appeared among beings, such as taking what is not given, condemning, lying, punishment and banishment. We ought to put aside evil and unwholesome things.

And they did so.

“They Put Aside Evil And Unwholesome Things” is the meaning of Brāhmin, which is the first regular title to be introduced for such people.

They made leaf‑huts in forest places and meditated in them. With the smoking fire gone out, with pestle cast aside, gathering almsfood for their evening and morning meals, they went away to a village, town or royal city to seek their food, and then they returned to their leaf‑huts to meditate. People saw this and noted how they meditated. “They Meditate” is the meaning of Jhāyaka, which is the second regular title to be introduced.

However, some of those beings, not being able to meditate in leaf‑huts, settled around towns and villages and compiled books. People saw them doing this and not meditating. “Now These Do Not Meditate” is the meaning of Ajjhāyaka, which is the third regular title to be introduced.

At that time it was regarded as a low designation, but now it is the higher. This, then, Vāseṭṭha, is the origin of the class of Brāhmins in accordance with the ancient titles that were introduced for them…

(Reference: DN 27)

In this Teaching from Gotama Buddha, he shares “the origin of the class of Brāhmins”.