Bhashya
एष यथोक्तगुण मे मम आत्मा अन्तर्हृदये हृदयपुण्डरीकस्यान्त मध्ये अणीयान अणुतर, व्रीहेर्वा यवाद्वा इत्यादि अत्यन्तसूक्ष्मत्वप्रदर्शनार्थम् ।श्यामाकाद्वा श्यामाकतण्डुलाद्वा इति परिच्छिन्नपरिमाणात् अणीयानित्युक्तेऽणुपरिमाणत्व प्राप्तमाशङ्कय, अत तत्प्रतिषेधायारभत-एष म आत्मा न्तर्हृदय ज्यायान्पृथिव्या इत्यादिना ।ज्याय परिमाणाच्च ज्यायस्त्व दर्शयन् अन तपरिमाणत्व दर्शयति-मनोमय इत्यादिना ज्यायानेभ्यो लोकेभ्य इत्यन्तेन ॥
In plain words
This Self of mine, dwelling deep within the lotus of the heart, is subtler than a grain of rice, subtler than a barley corn, subtler than a tiny millet seed. This comparison is given solely to illustrate its extreme, unimaginable subtlety. Yet, lest we mistake this subtlety for a limited, atomic size, the scripture immediately expands our vision: 'This Self within my heart is vaster than the earth, vaster than the heavens.' By showing it to be greater than any finite measure, the teaching reveals its truly infinite nature—all-pervading, made of pure consciousness, and vaster than all the worlds.
Close to the Sanskrit
This Self of mine, possessing the qualities mentioned, inside the heart, within the lotus of the heart, is subtler, more minute than a grain of rice or a barley corn, etc., for the purpose of showing extreme subtlety. Lest one should think it has a limited atomic size when it is said to be subtler than a limited measure like a millet seed or millet kernel, therefore, to negate that, the text begins: 'This Self of mine inside the heart is greater than the earth,' etc. Showing its greatness compared to large measures, it shows its infinite dimension by 'consisting of mind,' etc., up to 'greater than these worlds'.