अथैष श्लोको भवति—‘यतश्चोदेति सूर्यः, अस्तं यत्र च गच्छति’ इति प्रानाद्वा एष उदेति, प्राणेऽस्तमेति, ‘तं देवास्चक्रिरे धर्मम्, स एवाद्य, स उ श्वः’ इति । यद्वा एतेऽमुर्ह्यद्रियन्त तदेवाप्यद्य कुर्वन्ति । तस्मादेकमेव व्रतं चरेत्, प्राण्याच्चैवापान्याच्च, नेन्मा पाप्मा मृत्युराप्नु वदिति; यद्यु चरेत्समापिपयिषेत्, तेनो एतस्यै देवतायै सायुज्यं सलोकतां जयति ॥ २३ ॥
athaiṣa śloko bhavati—‘yataścodeti sūryaḥ, astaṃ yatra ca gacchati’ iti prānādvā eṣa udeti, prāṇe’stameti, ‘taṃ devāscakrire dharmam, sa evādya, sa u śvaḥ’ iti | yadvā ete’murhyadriyanta tadevāpyadya kurvanti | tasmādekameva vrataṃ caret, prāṇyāccaivāpānyācca, nenmā pāpmā mṛtyurāpnu vaditi; yadyu caretsamāpipayiṣet, teno etasyai devatāyai sāyujyaṃ salokatāṃ jayati || 23 ||
23. Now there is this verse: ‘The gods observed the vow of that from which the sun rises and in which he sets. It is (followed) to-day, and it will be (followed) to-morrow.’ The sun indeed rises from the vital force and also sets in it. What these (gods) observed then, they observe to this day. Therefore a man. should observe a single vow—do the functions of the Prāṇa and Apāna (respiration and excretion), lest the evil of death (fatigue) should overtake him. And if he observes it, he should seek to finish it. Through it he attains identity with this deity, or lives in the same world with it.
Now there is this verse or Mantra that brings out this very meaning: ‘The gods, fire and the rest, and the organ of speech etc. (in the body), in ancient times, after consideration observed the vow of that, viz. air and the vital force, from which the sun rises —externally he rises from air, and as the eye in the body, from the vital force— and in which, air and the vital force, he sets in the evening, and when a man goes to sleep. It is followed by the gods to-day, now, and it . will be followed by them to-morrow, in future. The words ‘followed by the gods’ are understood. Now the Brāhmaṇa briefly explains this Mantra: The sun indeed rises from the vital force and also sets in it, What is the meaning of the words, ‘The gods observed the vow of that…. It is (followed) to-day, and it will be (followed) to-morrow’? this is being stated: What vow these gods, Are and the rest and the organ of speech etc., observed then, i.e., the vow of air and of the vital force, they observe to this day, and will observe unbroken. But the vow of the organ of speech etc. and of fire and the rest is broken, for we see that at the time of setting, and when one falls asleep, they sink in air and the vital force respectively.
Similarly it has been said elsewhere, ‘When a man sleeps, his organ of speech is merged in the vital force, and so are the mind, the‘eye and the ear. And when he awakes, these again arise from the vital force. This is with reference to the body. Now with reference to the gods: When Are goes out, it sets in air. Hence they speak of it as having set. It indeed sets in air. And when the sun sets, he enters aií, and so does the moon; the quarters too rest on air. And they again arise from the air’ (Ś. X. iii. 3 6 – 8).
Because this one vow of air and the vital force, consisting of vibration or movement, persists in the gods such as fire and in the organ of speech etc.— since all the gods follow it alone, therefore a man, another person also, should observe a single vow. What is that? Do the functions of the Prāṇa and Apāna. The functions of these two, viz., respiration and excretion, never stop. Therefore, giving up the functions of all other organs, he should observe this one vow, lest the evil of death in the form of fatigue should overtake him. ‘Lest’ denotes apprehension. ‘If I swerve from this vow, I am sure to be overtaken by death’—with this dread at heart he should observe the vow of the vital force. This is the idea. And if he observes it, does take up the vow of the vital force, he should seek to finish it. If he desists from this vow, the vital force and the gods would be flouted. Therefore he must finish it. Through it, the observance of this vow of identification with the vital force, thinking, ‘The vocal and other organs in all beings as well as fire and the other gods are but a part and parcel of me, and I, the Vital force, the self, initiate all movement,’ he attains identity with this deity, the vital force, or lives in the same world with it. This latter result takes place when the meditation is not up to the mark.