oḿ tat sad iti nirdeśo
brahmaṇas tri-vidhaḥ smṛtaḥ
brāhmaṇās tena vedāś ca
yajñāś ca vihitāḥ purā
Translation of Bhagavad Gita 17.23
From the beginning of creation, the three words om tat sat were used to indicate the Supreme Absolute Truth. These three symbolic representations were used by brahmanas while chanting the hymns of the Vedas and during sacrifices for the satisfaction of the Supreme.
Commentary by Sri A.C. Bhaktivedanta Swami Prabhupada of Gaudiya Sampradaya:
It has been explained that penance, sacrifice, charity and foods are divided into three categories: the modes of goodness, passion and ignorance. But whether first class, second class or third class, they are all conditioned, contaminated by the material modes of nature. When they are aimed at the Supreme—om tat sat, the Supreme Personality of Godhead, the eternal—they become means for spiritual elevation. In the scriptural injunctions such an objective is indicated. These three words, om tat sat, particularly indicate the Absolute Truth, the Supreme Personality of Godhead. In the Vedic hymns, the word om is always found.
One who acts without following the regulations of the scriptures will not attain the Absolute Truth. He will get some temporary result, but not the ultimate end of life. The conclusion is that the performance of charity, sacrifice and penance must be done in the mode of goodness. Performed in the mode of passion or ignorance, they are certainly inferior in quality. The three words om tat sat are uttered in conjunction with the holy name of the Supreme Lord, e.g., om tad visnoh. Whenever a Vedic hymn or the holy name of the Supreme Lord is uttered, om is added. This is the indication of Vedic literature. These three words are taken from Vedic hymns. Om ity etad brahmano nedistham nama (Rig Veda) indicates the first goal. Then tat tvam asi (Chandogya Upanishad 6.8.7) indicates the second goal. And sad eva saumya (Chandogya Upanishad 6.2.1) indicates the third goal. Combined they become om tat sat. Formerly when Brahma, the first created living entity, performed sacrifices, he indicated by these three words the Supreme Personality of Godhead. Therefore the same principle has always been followed by disciplic succession. So this hymn has great significance.
Bhagavad-gita recommends, therefore, that any work done should be done for om tat sat, or for the Supreme Personality of Godhead. When one performs penance, charity and sacrifice with these three words, he is acting in Krishna consciousness. Krishna consciousness is a scientific execution of transcendental activities which enables one to return home, back to Godhead. There is no loss of energy in acting in such a transcendental way.
Commentary by Sri Vishvanatha Chakravarthi Thakur of Gaudiya Sampradaya:
Please see text 24 for Sri Visvanatha Cakravarti Thakur’s combined commentary to texts 23 and 24.
Commentary by Sri Ramanuja of Sri Sampradaya:
17.23 Here Brahman means the Veda. It is the secondary meaning of the expression, especially of the ritualistic portion of the Veda. The three-fold expression Om Tat Sat is connected with the Brahman or the Veda. Sacrifices and similar rituals are prescribed in the Vedas. These expressions Om Tat Sat are used in these Vedic rites. The connection of Om is that it should be invariably used at the commencement of the recitation of Vedic hymns. The syllable Tat and Sat indicate that these rituals are worthy of honour. The Brahmanas are those who are to preserve Vedic study as also the Vedas and the sacrificial rites ordained in them. All these were created by Me in the past. Sri Krsna elaborates in the next verses the nature of the connection of these syllables with the Vedic rituals, beginning first with Om.
Commentary by Sri Sridhara Swami of Rudra Sampradaya:
OM TAT SAT is renowned by the spiritually cognizant as the three fold manifestation of the brahman the spiritual substratum that pervades all existence representing potencies of the Supreme Lord Krishna. This is well established from the Vedic scriptures such as Taittiriya Upanisad I:VIII:I beginning om iti brahman om iti sarvam states: OM is synonymous with the Brahman. OM is understood to be the vibratory cause and spiritual substance of existence. OM is the transcendental sound vibration chanted before commencing every Vedic activity. TAT also is synonymous with the brahman as it signifies infallible, perfection and auspiciousness. SAT is as well synonymous with the brahman for it denotes the ultimate reality containing all realities. These three designations OM TAT SAT are profusely praised to exemplify that the have the potency to redeem and rectify any defects made while performing yagnas or acts of propitiation and worship to the Supreme Lord Krishna or any of His incarnations and expansions as revealed in Vedic scriptures. These threefold designations were manifested by the Supreme Lord to represent the Brahmanas, the Vedas and Vedic yagnas. OM represented the Brahmanas, TAT represents the Vedic scriptures and SAT represents the performance of Vedic yagnas for the satisfaction of the Supreme Lord. Therefore the three words OM TAT SAT are paramount in creation and eternally praiseworthy
Commentary by Sri Madhvacharya of Brahma Sampradaya:
Once again the Supreme Lord Krishna discourses on the modalities of performance of prescribed duties and the activities that are required to be performed by mentioning OM TAT SAT which is veritably the transcendental sound vibration and names of the Supreme Lord in His abstract form. In all creation His transcendental sound vibration OM is the root of all sounds and all pervasively always vibrating within and without. Since all the Vedic scriptures refer to the Supreme Lord with such veneration and reverence He is TAT and because the Supreme Lord is perfect without any defect and always auspicious He is SAT. In the subsidiary chapter of the Rig Veda the word OM is referred to His potency of the brahman which is the spiritual substratum pervading all existence. TAT refers to Himself as the source of the Brahman and SAT denotes that He is the original creator of all existence. The elevated Vaisnavas and Brahmins from one of the four sampradaya’s or authorised channel of disciplic succession as revealed in Vedic scriptures are ordained to vibrate these transcendental sound vibrations when commencing, executing and concluding all Vedic rites.
Commentary by Sri Keshava Kashmiri of Kumara Sampradaya:
In this manner the three gunas or modes of material nature in relation to Vedic sctivities has been explained by Lord Krishna emphasising that aspirants for moksa or liberation from material existence should only perform activities characterised by sattva guna or mode of goodness and should avoid activity that is characterised by raja guna the mode of passion and tama guna the mode of ignorance. During the performance of yagna or propitiation, tapah or austerities and dana or charity; if by chance there is any mistake or error in the subservient components regarding time, place, ingredients and recitation of prescribed mantras or Vedic chants. Such qualified devotees firmly situated in sattva guna possessing purity of heart derived from eating sanctified foods situated in sattva guna and due to performing all activities with bhakti or exclusive loving devotion and also because they are not expectant of any reward for the yagnas they perform and therefore free from any karmas or reactions to actions. Even if such a one commits the sin of improper execution of Vedic rites or incurs the demerits of lapse in attention or forgetfulness of ingredients or inappropriate recitation of Vedic mantras. The most merciful Supreme Lord Krishna in order to protect and safeguard His devotees from acquiring such sins and demerits instructs the utterance of the three divine syllables OM TAT SAT which bestows all virtues and blessings and insures protection, and is glorified by the enlightened sages and liberated muni’s and by knowers of the Vedic scriptures. The enlightened agree unanimously that OM TAT SAT are threefold based on similarity of qualities and attributes related to the brahman or spiritual substratum pervading all existence, related to the Vedic scriptures and related to the Supreme Lord.
We find that the Taittiriya Upanisad I.VIII.I beginning om iti brahman om iti sarvam states: OM is the brahman and OM is the ultimate. The Mundaka Upanisad II.II.VI beginning: om ityevam dhyavatha atmanam states: One should meditate upon OM as representing the Supreme Lord. The Chandogya Upanisad VI.VIII.I beginning sa ya esho anima itad states: That which is the fundamental cause of all existence, which is the spiritual substratum of all existence, which is referred to as Thou art that, is the brahman which manifests from OM whose source is the Supreme Lord. The pranava OM is declared to be the name for the personal aspect of the Supreme Lord. Pranava means first breath mad is the transcendental sound vibration OM commencing all Vedic rites. It is from the root prana meaning breath. TAT is declared to be perfection aspect of the brahman and SAT is declared to be the creational aspect of the brahmin. They are all supremely auspicious and all Vedic rites begin and end with OM.
At the dawn of creation the Supreme Lord emanated the Vedic scriptures, the Vaisnava and brahmanas and yagna to evolve and protect creation. All prescribed Vedic rites were originated and ordained by the Supreme Lord. By remembering the threefold syllables OM TAT SAT and by vibrating their transcendental sound frequency, the potency to neutralise and eradicate any inauspiciousness or error in the performance of any prescribed Vedic rite is activated and no sin is committed nor demerit incurred. This potency is perpetual throughout all eternity and is solely available exclusively to the duly initiated Vaisnavas and brahmanas from one of the four authorised sampradayas or channels of disciplic succession as revealed in Vedic scriptures.
Commentary by Sri Adi Shankaracharya of Advaita Sampradaya:
17.23 Om, tat, sat-iti, this; is smrtah, considered, regarded, in the Vedanta, by the knowers of Brahman; to be the trividhah, threefold; nirdesah, designation, mention by name-nirdesa is that by which a thing is specified; brahmanah, of Brahman. The Brahmanas and the Vedas and the sacrifices were vihitah, ordainded, [When some defect arises in sacrifice etc., then this is corrected by uttering one of these words-Om, tat, sat.] created; tena, by that threefold designation; pura, in the days of yore [In the beginning of creation by Prajapati.]-this is said by way of eulogizing the designation.
Commentary by Sri Abhinavagupta of Kaula Tantra Sampradaya:
17.23-27 Om etc. upto abhidhiyate. An indication of the Brahman i.e., an act of facing (or aiming at) the Brahman is made by these three words viz., OM, TAT and SAT. Of them, Om indicates that ‘This purport of the scriptures is [to be ?] accepted as long as one has bodily connection’. The pronoun TAT, which denotes generality and which is incapable of denoting exclusively a particular, mentions, as far as the Brahman is concerned, the absence of intention for fruit. An intention is not possible without reference to something particular. No doubt [TAT] may denote all particulars [in general]. But it would lead to intending the fruits and the doer-ship with regard to all [in general]. Even then [the Brahman] cannot have connection with any particular fruit. The Vedic word SAT denotes ‘prasie’. The act, like this sacrifice etc., though perormed, truns out to be an act of the Tams (evil act) if it is performed with the idea, ‘It is an evil act’. Further, what is performed with an intention for a particular fruit is not praiseworthy, and it causes nothing but bondage. Therefore, those, who bear in mind, ‘This is a thing to be performed’ – they are not fettered, even though they perform acts like sacrifice etc. With this idea only, it has been said in the Adiparvan as – ‘The austerity is not dirt, nor the [Vedic] study, nor the natural ritual enjoined by the Vedas, and nor the act of earning wealth by all efforts. But, if they are struck by mind, they themselves become dirt.’ (MB, Adi. i, 210). [Here in this passage] dirt that which fetters. Natural : [That is, ordained ], such as – ‘Without expecting anything, a Brahman should learn the Vedas etc., together with their six subsidiaries’ etc. By all effort : by the act that is suitable and is well known in the scriptures and in the worldly practice. By mind : by the mind that is yoked to the traid of the Strands, Sattva etc. [Those actions that] have been simply ruined [by that mind], are binding and not otherwise. This is the idea here. Therefore, the acts like sacrifice etc., and the acts, like acquiring [Wealth] etc., for that purpose, have to be perfored as being inevitable as long as the body exists. Or, perhaps, the word OM conveys [with regard to the Brahman] the idea of That in Which the entire universe has been totally calmed down. TAT conveys the idea of That of the nature of Sovereign Independence of Will, which is nothing but comprehending the rising waves in the form of the universe. And the word SAT denotes the act of manifestation by the Brahman – even though It is complete in Itself – as [the universe] having varied nature, a manifestation that causes differences (or duality) expanding under the weight of its Sovereign Independenc of Will. Hence it has been said ‘In the sense of manifesting as beings and in the sense of manifesting perfectly [SAT is employed].’ Thus, having is front [as a casue] that aspect (the Soul) of highly tranquil nature; and having in the centre that aspect which is well connected with desire-waves viz., the desire to make gift, the desire to perform sacrifice and the desire to observe penance; this final body radiates (or dances) filled with a group of activities, such as offering gift, performing sacrifice and observing austerity, and of what are conducive to them. This triad is indeed simultaneously the inherent nature of the Unhindered One (the Soul). So, what fruit could be there ? And to whom ? How ? Whence ? Where ? And by what means ? The act of person, with no faith, is an act of the Tamas and bears no fruit in any way and bears fruit which is nothing but the labour undertaken in bringing together the band of means [of those acts]. Hence one should not on any account remain faithless. This is being said now :
Sanskrit Shloka Without Transliteration Marks:
om tat sad iti nirdeso
brahmanas tri-vidhah smrtah
brahmanas tena vedas ca
yajñas ca vihitah pura
Sanskrit to English Word for Word Meanings:
oḿ — indication of the Supreme; tat — that; sat — eternal; iti — thus; nirdeśaḥ — indication; brahmaṇaḥ — of the Supreme; tri-vidhaḥ — threefold; smṛtaḥ — is considered; brāhmaṇāḥ — the brāhmaṇas; tena — with that; vedāḥ — the Vedic literature; ca — also; yajñāḥ — sacriﬁce; ca — also; vihitāḥ — used; purā — formerly.