Verse 3.42
श्रोत्राअकाशयोः संबन्धसंयमात् दिव्यं श्रोत्रम् ॥४२॥
śrotra-ākāśayoḥ saṁbandha-saṁyamāt divyaṁ śrotram ॥42॥
By making Samyama on the relation between the ear and the Akasa comes divine hearing.
Verse 3.43
कायाकाशयोः संबन्धसंयमात् लघुतूलसमापत्तेश्चाअकाश गमनम् ॥४३॥
kāyākāśayoḥ saṁbandha-saṁyamāt laghu-tūla-samāpatteśca-ākāśa gamanam ॥43॥
By making Samyama on the relation between the Akasa and the body the Yogi becoming light as cotton wool goes through the skies.
There is the Akasa, the ether, and the instrument, the ear. By making Samyama on them the Yogi gets divine hearing; he hears everything. Anything spoken or sounded miles away he can here.
This is one of the supernatural powers called laghima, or becoming as light as cotton.
In the puranas, it is said that Lord Hanuman (son of the Wind God) jumped up to the sky to fetch the sun, which he thought was an apple.
There is also the story from the Ramayan that he leaped to the Himalayas to fetch the elixir of life, called sanjeevani to save the life of Lord Rama’s brother who was wounded in a fight with Ravana’s son. Narada, who composed the Bhakti Satras, is said to wander in the three worlds from time immemorial to this day.
This Akasa is the material of this body; it is only Akasa in a certain form that has become the body. If the Yogi makes Samyama on this Akasa material of his body, it acquires the lightness of Akasa, and can go anywhere through the air.
PATANJALI YOGA SUTRAS