From Roberto Calasso’s Ardor:
Having listed the other sacrifices, the sacrifice to brahman still has to be described. And so we read: “The sacrifice to brahman is the daily study of the Veda.” There is a line that starts off with the sacrifice as a long ceremony, structured into hundreds of movements and actions—and therefore entirely visible—and which leads up to a later and invaluable variant, the sacrifice as an invisible and imperceptible activity, as it is performed through the study of the Veda.
Study of the Veda, known as svādhyāya or “inner recitation,” had to be done beyond the confines of the village, to the east or north, where the roofs were out of sight. It was the first indication of a process by which the simple acquisition of knowledge would get gradually more distant from society and unshackled by it. But study could also be carried out in other ways, even in bed: “And, in truth, if he studies his lesson, even stretched out on a soft bed, oiled, adorned and completely fulfilled, he is burned by tapas up to the tips of his fingernails: and so the daily lesson must be studied.” Here we see a figure we thought was modern: the reader, described much as the young Proust might have been described, given over to his journées de lecture. Once again we can see Vedic open-mindedness: to practice tapas we don’t have to cross our legs or subject ourselves to those “mortifications” that some regard as the very meaning of the word tapas. No, even luxe, calme et volupté may help—or at least not hinder. It is enough that the fervor of the mind runs without respite, and burns “up to the tips of the fingernails.