He is my self within the heart, smaller than a corn of rice, smaller than a corn of barley, smaller than a mustard seed, smaller than a canary seed or the kernel of a canary seed. He also is my self within the heart, greater than the earth, greater than the sky, greater than heaven, greater than all these worlds.

In plain words: This Self lives inside my heart and is tinier than a grain of rice or a mustard seed. Yet this same Self is bigger than the earth, the sky, heaven and all the worlds together.