Text:

ऊर्ध्वं प्राणमुन्नयत्यपानं प्रत्यगस्यति ।
मध्ये वामनमासीनं विश्वे देवा उपासते ॥ ३ ॥

ūrdhvaṃ prāṇamunnayatyapānaṃ pratyagasyati |
madhye vāmanamāsīnaṃ viśve devā upāsate || 3 ||

3. He leads the prana upwards and casts the apana downwards; the dwarf seated in the middle, all Devas worship.

Shankara’s Commentary:

Com.—In realising the existence of the atman an evidence is offered—Upwards] from the heart. Praba the wind, whose function is connected with breath. Unnayati ] leads upwards. Similarly casts the apana downwards. The word yah (who), should be supplied to complete the sentence. Him seated in the middle, i.e., in the akas of the lotus of the heart, with the light of knowledge clearly shining in the intellect and worthy of worship, all the Devas, i.e., the senses, the eyes and the rest propitiate, by bringing in the perceptions of form, etc., as the subjects please the king, by offerings, i.e., they are uninterruptedly active on his account. The drift of the text is that there is another on whose behalf and by whom is directed all the activity of the winds and the senses.