तौ वा एतौ द्वौ संवर्गौ वायुरेव देवेषु प्राणः प्राणेषु ॥ ४.३.४ ॥
tau vā etau dvau saṃvargau vāyureva deveṣu prāṇaḥ prāṇeṣu || 4.3.4 ||
4. These two swallow everything: air among the gods and prāṇa among the organs.
Tau vai etau dvau, these are those two; samvargau, all-swallowing; vāyuḥ eva deveṣu, the air among the gods; prāṇaḥ prāṇeṣu, prāṇa [the vital breath] among the organs.
Briefly, vāyu, air, is the source of fire, the sun, the moon, and water. Therefore one should worship vāyu as outside, in nature (adhidaivata). Likewise, prāṇa, the vital breath, is the source of speech, the eyes, the ears, and the mind, and therefore one should worship this prāṇa as within oneself (adhyātma).