The thirteenth sutta of the Digha Nikáya, preached to Vásettha and Bháradvája who visited the Buddha at Manasákata.
The Buddha points out the futility of the belief that a mere knowledge of the Three Vedas leads to the attainment of reunion with Brahmá.
Such union can, however, be attained only by the practice of the four Brahma-viháras. D.i.235-53.