Yoga Sutras 3.46
Patanjali, explained by Swami Vivekananda
ततोऽणिमादिप्रादुर्भावः कायसम्पत्तद्धर्मानभिघातश्च ॥
tato'ṇimādiprādurbhāvaḥ kāyasampattaddharmānabhighātaśca
From that comes minuteness and the rest of the powers, "glorification of the body," and indestructibleness of the bodily qualities.
In plain words: From mastering the elements come powers like becoming tiny or huge, heavy or light. The body also becomes perfected, and nothing can harm it.
Swami Vivekananda explains
This means that the Yogi has attained the eight powers. He can make himself as minute as a particle, or as huge as a mountain, as heavy as the earth, or as light as the air; he can reach anything he likes, he can rule everything he wants, he can conquer everything he wants, and so on. A lion will sit at his feet like a lamb, and all his desires will be fulfilled at will.