Mbh 12.263.2b

From rain springs food. From food are born living creatures. In former days, men righteously devoted to Sacrifices used to obtain therefrom the fruition of all their wishes. The earth yielded crops without tillage. The blessing uttered by the Rishis produced herbs and plants.[1167] The men of former times never performed Sacrifices from desire of fruits and never regarded themselves as called upon to enjoy those fruits. Those who somehow perform sacrifices, doubting the while their efficacy take birth in their next lives as dishonest, wily, and greedy men exceedingly covetous of wealth. That man who by the aid of false reasoning holds up all the authoritative scriptures as fraught with evil, is certain to go, for such sinful act of his, into the regions of the sinful. Such a man is certainly possessed of a sinful soul, O foremost of Brahmanas, and always remains here, bereft of wisdom.[1168] That man who regards those acts obligatory which have been laid down in the Vedas and directed to be accomplished every day, who is penetrated with fear if he fails to accomplish them any day, who takes all the essentials of Sacrifice as identical with Brahma, and who never regards himself as the actor, is truly a Brahmana.[1169] If the acts of such a person become incomplete, or if their completion be obstructed by all unclean animals, even then those acts are, as heard by us, of superior efficacy. If, however, those acts are done from desire of fruit (and their completion be obstructed by such impediments), then expiation would become necessary. They who covet the acquisition of the highest object of life (viz., Emancipation), who are bereft of cupidity in respect of all kinds of worldly wealth, who discard all provision for the future, and who are freed from envy, betake themselves to practice of truth and self-restraint as their Sacrifice.