Mbh 12.232.1c

Determined in respect of character by either injuriousness or peacefulness, mildness or fierceness, righteousness or unrighteousness, truthfulness or untruthfulness, each creature, at every new creation, obtains that particular attribute which it had cherished before. It is in consequence of this that that particular attribute attaches to it. It is the Ordainer himself who attaches variety to the great entities (of Space, Earth, etc.), to the objects of the senses (such as form, etc.), and to size or bulk of existent matter, and appoints the relations of creatures with those multiform entities. Amongst men who have devoted themselves to the science of things, there are some who say that, in the production of effects, exertion is supreme. Some learned persons say that Destiny is supreme, and some that it is Nature which is the agent. Others say that Acts flowing from (personal) exertion, and Destiny, produce effects, aided by Nature. Instead of regarding any of these as singly competent for the production of effects, they say that it is the union of all three that produces all effects. As regards this subject,[884] some say that such is the case; some, that such is not the case; some, that both of these are not the case; and some, that it is not that the reverse of both are not. These, of course, are the contentions of those that depend on Acts, with reference to objects. They however, whose vision is directed to truth regard Brahma as the cause.[885] Penance is the highest good for living creatures. The roots of penance are tranquillity and self-restraint. By penance one obtains all things that one wishes for in one's mind. By penance one attains to that Being who creates the universe. He who (by penance) succeeds in attaining to that Being becomes the puissant master of all beings. It is by Penance that the Rishis are enabled to read the Vedas ceaselessly.