That which cannot be seen, nor seized, which has no family and no caste, no eyes nor ears, no hands nor feet, the eternal, the omnipresent (all-pervading), infinitesimal, that which is imperishable, that it is which the wise regard as the source of all beings."

In plain words: The wise see the source of all beings as something that cannot be seen or grabbed. It has no family and no caste, no eyes, ears, hands or feet. It is eternal, everywhere, extremely subtle and never destroyed.