Śaṅkaraon Brahma Sūtra 2.3.44

A mantra also intimates the same view. ‘ Such is the greatness of it greater than it is the Person. One foot ; of it are all beings, three feet of it are the Immortal in heaven’ {K/t, Up. Ill, 12, 6). Here the word ‘beings* denotes all moving. and non-moving things, among which the souls occupy the first place; in accordance with the use of the word in the following passage, * Not giving pain to any being (bhfita) except at the tirthas’ {KA, Up. VII I, — 15). Herefrom also we conclude that the individual soul is a part of the Lord. And again from the following reason.