Bhashya
मनःस्पन्दितं तदभावे दृगेवाविशेषेण प्राणात्मना अवस्था-नात्प्राणः, 'प्राणो ह्येवैतान्सर्वान्संवृङ्क्ते' इति श्रुतेः ।तैजसःहिरण्यगर्भः, मनस्यवस्थितत्वात् ।लिङ्गं मनः, 'यत्र मनो-मयोऽयं पुरुषः' इत्यादिश्रुतेः ।ननु व्याकृतः प्राणः सुषुप्तेतदात्मकानि कारणानि भवन्ति कथमव्याकृतता ।नैष दोषः,अव्याकृतस्य देशकालविशेषाभावात् ।यद्यपि प्राणाभिमानेसति व्याकृततैव प्राणस्य, तथापि पिण्डपरिच्छिन्नविशेषाभि-माननिरोधः प्राणे भवतीत्यव्याकृत एव प्राणपरिच्छिन्ना-भिमानवतां यथा प्राणलये परिच्छिन्नाभिमानिनां प्राणे अ-व्याकृतता, तथा प्राणाभिमानिनोऽपि अविशेषापन्नत्वात्अव्याकृतता, समाना ।प्रणवबीजात्मकत्वं च तदध्यक्षश्चएको व्याकृतावस्थः परिच्छिन्नाभिमानाध्यक्षाणां च तेनै-कत्वमिति पूर्वोक्तं विशेषणम् एकीभूतः प्रज्ञानघनः इत्याद्युप-पन्नम् ।तस्मिन्नुक्तहेतुत्वात् प्राणशब्दत्वमव्याकृतस्य, 'प्राण-बन्धनं हि सोम्य मनः' इति श्रुतेः ।एवं तावत्प्रभवा-प्ययौ हि भूतानामित्यनेन एकविज्ञानेन सर्वविज्ञानंदर्शितम् ।तथा माण्डूक्यश्लोके जागरितावस्थायामेवा-वस्थात्रयमुक्तं तस्यामेवावस्थायां तत्रैविध्ये मनोव्यापारंव्यावृत्य प्रागुक्तोपास्ये मनोव्यापारं प्रवर्तयितुम् उपास्य-कुर्यादिति ।एषा वै महालक्ष्मीः यजुर्गायत्री महतीनां महालक्ष्म्यादीनां प्रतिपादकत्वात् महालक्ष्मीः सावित्रमन्त्रे अत्र च यजुरिति वदन् सामाङ्गत्वेऽपि गीतिरहितमङ्गद्वयमिति दर्शयति ।प्रणवान्तर्भावाय अक्षराणि गणयति चतुर्विंशदक्षरा भवतीति ।चतुर्विंशदिति च्छान्दसम् ।गायत्री वा इदं तृतीयमङ्गं सर्वं कृत्स्नं यदिदं किंच ।यस्मादेवं तस्मात् य एतां शिखां पारमेश्वरीं महालक्ष्मीं याजुषीं प्रागुक्तविग्रहशक्त्युपास्यां वेद उपास्ते, तस्य फलं निर्दिशति— महतीं श्रियमश्नुत इति; महतीं श्रियं प्राप्नोतीत्यर्थः ।एतद्वायव्युक्ताः शक्तयः विग्रहवत्यः अभिषेकनशक्तीनामुपकाराय अमृतमयीं शिखाम् अमृतस्रवणाय तद्बन्धनाय वा उपास्ते इति तत्त्वार्थः ।एवं तावन्नृसिंहब्रह्मविद्योपकारिणीं सामाङ्गतृतीयाङ्गविद्यामभिधाय अथेदानीं सामाङ्गचतुर्थाङ्गविद्यां नृसिंहगायत्रीमाह ।ॐ प्रणवः व्याख्यातः तदङ्गं कवचाख्यं पारमेश्वरम् ।धीमहीति ध्यायेमहि ।किमर्थं वज्रनखाय नृसिंहाय ।तादर्थ्ये चतुर्थी ।तदर्थं विद्महे जानीमः यतः तदेवाङ्गं नः अस्मान् सिंहः प्रचोदयात् इत्युक्तार्थम् ।नरशब्दं विहाय सिंह इति वदन् अस्यां विद्यायां सिंहाकारस्य प्राधान्यं दर्श-यति ।इति-शब्दो मन्त्रसमाप्तिं द्योतयति ।एषा वै नृसिं-हगायत्री नृसिंहार्थकवचप्रतिपादकत्वाद्गायत्री प्रणवान्तर्भावंदर्शयति ।कवचआश्रिततदावृतहृद्यान्तर्गतानां वेदानां देवानांयथायोग्यतया निदानं मूलकारणं भवति ।उपासकस्यफलं निर्दिशति ।य एवं वेद स निदानवान्भवतीति ।तत-श्चायमर्थः ।पारमेश्वरं कवचाख्यमङ्गं कृत्सबन्धि सर्ववेद-निदानत्वेनोपास्यं तत्प्रतिपादकत्वात् ऋक्संबन्धि सर्ववेददे-वनिदानं गायत्री उच्यते इति तत्त्वार्थः ॥
In plain words
When that flicker of mind falls away entirely, all that remains is seeing itself, undivided, resting simply as the vital breath — which is why this state is called 'Prāṇa': the scripture says the breath draws every faculty back into itself. The dream-self is 'Taijasa', and also 'Hiraṇyagarbha', because it lives in the mind; the subtle body just is the mind, as the scripture says, 'this person is made of mind'. But someone may object: the breath is already a differentiated thing, and in deep sleep the causal faculties, made of that very breath, are still present — so how can we call this state undifferentiated? There's no real problem here, because 'undifferentiated' simply means having no particular place or time of its own. Granted, so long as we identify with the breath, the breath itself stays differentiated; but the identification bound to this one particular body dissolves in the breath, and that dissolving is exactly what makes it 'undifferentiated' for anyone whose sense of self was tied to an individual breath — the same way, when the breath itself dissolves, undifferentiation appears within the cosmic breath for those whose identification had been so bound. And because the one identified with the cosmic breath has reached that very same non-distinction, the two cases are really one and the same. Add to this that it carries Om as its seed, and that its single presiding power, standing in the differentiated state, is one with the powers presiding over every bounded identification — and now every earlier description falls into place: 'become one', 'a mass of pure awareness', and the rest. That is exactly why the undifferentiated state is called by the name 'Prāṇa' — as the scripture puts it, 'mind, dear one, is tethered to the breath.' In this one line, 'the origin and dissolution of beings', a single piece of knowledge is shown to unlock knowledge of everything. In just the same way, the Māṇḍūkya verse locates all three states within waking alone: in whichever of its three modes you find yourself, you withdraw the mind's wandering and turn it deliberately toward what was described earlier as the object of meditation. This is Mahālakṣmī herself, the Yajur-Gāyatrī, because she gives voice to the great goddesses headed by Mahālakṣmī. By calling this a 'Yajus' verse, alongside the Sāvitrī elsewhere, he shows that, limb of the Sāman though it is, this pair of limbs carries no melody. And to fold Om into the count, he tallies the syllables: twenty-four in all — a Vedic-metrical count, meaning this is truly the Gāyatrī metre. This third limb is everything, the whole of whatever this world contains, and more besides. So whoever knows and meditates on this crest-mantra of the Supreme Lord — Mahālakṣmī, of the Yajur-Veda, worshipped as the very embodiment of power already described — reaps a clear reward: 'he attains great fortune.' These powers, given voice through the vital wind and clothed in form, are meditated upon for the sake of the powers invoked at consecration, upon this nectar-made crest, so that immortality's nectar might flow, or else be held fast. Having now laid out this third limb that serves the Narasiṃha-Brahman teaching, he turns to the fourth: the Narasiṃha-Gāyatrī. Om, the praṇava, needs no further explanation. This next limb, called the Kavaca, the armor, belongs to the Supreme Lord: 'dhīmahi' — we meditate; on whom? — on Narasiṃha, diamond-clawed (the dative marking purpose); 'vidmahe' — we know; because — 'may the Lion himself, our very own armor, drive us onward.' By dropping the word 'man' and keeping only 'lion', he makes plain that in this teaching it is the lion-nature that comes first. The closing 'iti' simply marks that the mantra is complete. This is the Narasiṃha-Gāyatrī: because it voices the meaning of the Narasiṃha armor, it is called a Gāyatrī, and it shows Om folded within it. For every Veda and every deity that rests within the heart this armor encloses, it becomes, each in its own measure, the very root and ground. And the reward for the one who worships it is stated plainly: whoever knows this becomes one who holds that ground within himself. So the sense comes to this: this armor-limb, belonging to the Supreme Lord, touches everything, and is to be worshipped as the foundation of every Veda; and because it expounds that foundation, tied to the Ṛg-Veda, it is rightly called the Gāyatrī — the ground of every Veda and every god.
Close to the Sanskrit
In the absence of that vibration of mind, since seeing (consciousness) alone remains, without distinction, abiding purely as the vital breath, [this state] is [called] 'Prāṇa' — by the śruti-passage 'the vital breath indeed draws all these into itself'. [The dream-state self is called] 'Taijasa', [and also] 'Hiraṇyagarbha', because it abides in the mind. The 'subtle body' is the mind, by such a śruti-passage as 'where this person is made of mind'. Objection: the vital breath is [itself already] differentiated, [and] in deep sleep the causal [faculties], having that [breath] as their nature, come to be — how then is [that state] undifferentiated? This is no fault, because the undifferentiated has no particular distinction of place or time. Although, when there is self-identification with the vital breath, differentiation does indeed belong to that breath, nevertheless the cessation of the self-identification bounded by the particular body occurs in the breath; thus it is indeed 'undifferentiated' for those whose self-identification is bounded by the [individual] breath — just as, at the dissolution of the [individual] breath, there is undifferentiation, in the [universal] breath, for those whose self-identification was [previously] bounded, so too, for the one identified with the [universal] breath as well, there is undifferentiation, because of having arrived at that same non-distinction; [the two cases] are equivalent. And [there is] the fact of having the syllable Om as seed, and [the fact that] its single overseer, abiding in the differentiated state, is one with the overseers of the [individual] bounded self-identifications — by that, [there is] the unity earlier spoken of; [thus] the previously stated qualifying epithets — 'become one', 'a mass of cognition', and the rest — are [all] accounted for. Because of that stated reason, the name 'Prāṇa' [applies] to the undifferentiated, by the śruti-passage 'the mind, O gentle one, is indeed tethered to the vital breath'. Thus, by the statement 'the origination and dissolution of beings' — through this single [item of] knowledge, knowledge of everything has been shown. Likewise, in the verse of the Māṇḍūkya [Upaniṣad], the threefold state was said to occur within the waking state alone; [the rule is that] in that very [waking] state, in [any] one of its three divisions, having withdrawn the mind's activity [from other objects], one should direct the mind's activity toward the previously-stated object of meditation, and so meditate. This [verse] is indeed Mahālakṣmī, the Yajur-Gāyatrī, because it expounds the great goddesses beginning with Mahālakṣmī; [hence it is] Mahālakṣmī. In the Sāvitrī-mantra [elsewhere], and here too, by calling it 'Yajus' he shows that, even while being a limb belonging to the Sāman, this pair of limbs [i.e. this Yajus-limb and the following one] is without sung chanting. In order to include the syllable Om [within the count], he counts the syllables: it comes to twenty-four syllables. 'Twenty-four' is a metrical [Vedic] figure — [that is,] this is indeed the Gāyatrī [metre]. This third limb is all, entire, whatever this [world] is, and whatsoever else. Since this is so, therefore: whoever knows and meditates on this crest-mantra belonging to the Supreme Lord, [called] Mahālakṣmī, belonging to the Yajur-Veda, worshipped as the previously-stated embodied power — the text specifies his fruit: 'he obtains great fortune' — that is, he attains great prosperity, that is the meaning. These powers, manifested through the vital wind, possessed of embodied form, are meditated upon — for the sake of the powers of the consecration-rites, upon the crest-mantra made of the nectar of immortality, for the streaming forth of that nectar, or for its retention: that is the essential sense. Thus, having now expounded the third-limb teaching, belonging to the Sāman, helpful to the Narasiṃha-Brahman doctrine, he now states the fourth-limb teaching, belonging to the Sāman, [namely] the Narasiṃha-Gāyatrī. 'Om' — the praṇava — has already been explained. That limb, called the 'Kavaca' (armor), belongs to the Supreme Lord. 'Dhīmahi' [means]: 'let us meditate'. For what purpose? — 'for the diamond-clawed Narasiṃha'; the dative case is used here in the sense of purpose. 'Vidmahe' [means]: 'we know'. Because: 'that very limb [i.e. mantra] — may the Lion impel us' — [us being] 'asmān' — this is the stated meaning. By setting aside the word 'man' and saying [only] 'lion', he shows, in this teaching, the predominance of the lion-form. The word 'iti' signals the conclusion of the mantra. This is indeed the Narasiṃha-Gāyatrī; because it expounds, in meaning, the Narasiṃha-armor, it is [called] the Gāyatrī; it shows the inclusion of the syllable Om [within it]. Of the Vedas and the deities resting upon, enclosed within, and abiding within the heart on which the armor-mantra rests, it becomes, each according to its fitness, the basis, the root cause. The text specifies the fruit for the worshipper: whoever knows this becomes one possessed of that [cosmic] basis. Hence the sense is this: the limb called the armor-mantra, belonging to the Supreme Lord, connected with everything, is to be worshipped as the basis of all the Vedas; because it expounds that, connected with the Ṛg[-Veda], it is called the Gāyatrī, the basis of all the Vedas and deities — that is the essential sense.