bhūta-sūkṣmātmani mayi
tan-mātraḿ dhārayen manaḥ
aṇimānam avāpnoti
tan-mātropāsako mama
bhuta-sukshma -- of the subtle elements; atmani -- in the soul; mayi -- in Me; tat-matram -- on the subtle, elemental forms of perception; dharayet -- one should concentrate; manah -- the mind; animanam -- the mystic perfection called anima; avapnoti -- obtains; tat-matra -- in the subtle elements; upasakah -- the worshiper; mama -- My.
Anima refers to the mystic ability to make oneself smaller than the smallest and thus able to enter within anything. The Supreme Personality of Godhead is within the atoms and atomic particles, and one who perfectly fixes his mind in that subtle atomic form of the Lord acquires the mystic potency called anima, by which one can enter within even the most dense matter such as stone.