13.31 When he perceives that the diversified 'modes of existence' of all beings as men, divinities etc., are founded on the two principles of Prakrti and Purusa; when he perceives that their existence as divine, human, short, tall etc., is rooted in 'one' common foundation, namely, in the Prakrti, and not in the self; when he sees that 'their expansion', i.e., the successive proliferaton into sons, grandsons and such varieties of beings, is from Prakrti alone - then he reaches the brahman. The meaning is that he attains the self devoid of limitations, in Its pure form of knowledge.