यदा भूतपृथग्भावमेकस्थमनुपश्यति।
तत एव च विस्तारं ब्रह्म सम्पद्यते तदा।।13.31।।
।।13.31।।जिस कालमें साधक प्राणियोंके अलगअलग भावोंको एक प्रकृतिमें ही स्थित देखता है और उस प्रकृतिसे ही उन सबका विस्तार देखता है? उस कालमें वह ब्रह्मको प्राप्त हो जाता है।
Lord Krishna is stating that one must realizes that all the diversity of forms throughout creation is manifested by the medium of prakriti or the material substratum pervading physical existence which gives rise to unlimited bodies and their correlating senses. All jivas or embodied beings whether demigods, humans or animals are constituted of the dual natures of purusa the supreme spirit and prakriti. The compound word eka-stham meaning situated in one refers to the singularity of prakriti which the ksetra or sphere of activity exists within. The word vistaram meaning expansion refers to the variegated myriads of differentiated existences in successive form manifestations such as children, grandchildren, great grandchildren all uniquely emanating from the same principle of prakriti. Whosoever understands that all external appearing differences have their origin in prakriti and not in purusa or the supreme spirit nor paramatma the supreme soul; such a person attains the realization of the brahman or spiritual substratum pervading all existence.
