Oṁ tat sat is a sūtra, or a concise statement of truth, in the Upaniṣads, which are ancient Hindu scriptures. One chants Oṁ tat sat to remember Bhagavān, the Supreme Lord, before starting any auspicious activity, and upon its completion to offer the results to Bhagavān.
The Meaning of Oṁ
Oṁ means otaṁ protam iti oṁ, which means “He who is pervading and protecting is Oṁ”. Oṁ is Bhagavān’s official name, because He is otam protam or sarva-vyāpi (omnipresent). He is present everywhere, inside, outside, and in all directions. He is also sarvajña (omniscient). Because He is sarvajña and sarva-vyāpi, He is sarva-śaktimān (omnipotent), because He is all great,therefore He is addressed as Oṁ.
When one chants Oṁ, he remembers Bhagavān’s three qualities: sarva-vyāpi, sarvajña, and sarva-śaktimān. All mantras in Vedas and Upaniṣads begin and end with Oṁ.
Puruṣa-sūkta in Ṛg Veda starts with Oṁ -Oṁ sahasraśīrṣā puruṣaḥ and ends with Oṁ. Viṣṇu Sahasra-nāma starts with Oṁ –oṁ viśvaṁ viṣṇuḥ vaṣaṭkāro and ends with Oṁ. However, Gaudiya devotees are not interested in Oṁ much. They are interested in Bhagavān’s beauty and all attractiveness. Therefore, they address Bhagavān as Kṛṣṇa. We don’t love Kṛṣṇa because He is great,we love Him because He is Kṛṣṇa.
Dhyānīs and jñānīs address and meditate on Bhagavān as Oṁ. By addressing Him as great, they create a barrier or distance between themselves and Him. We don’t want to have any gap between Bhagavān and us. Therefore, we are not interested in Oṁ.
The Role of Oṁ in Hindu Rituals
Śāstras, or scriptures, recommend chanting oṁ before reading Vedas and performing yajña and pūja, which are rituals of sacrifice and worship. In Sanātana dharma, or the eternal way of life, there is no activity without chanting Oṁ. If one is on the path of pūja, dhyāna and jñāna, which are the paths of meditation and knowledge, one should chant Oṁ. But if one is on the path of prem, which is the path of love, he need not chant Oṁ .
Another Meaning of Oṁ
According to Matsya Purāṇa and Agni Purāṇa, which are ancient Hindu texts, the sound Oṁ consists of three letters: auṁ. Akārena iti Kṛṣṇa; ‘a’ means Kṛṣṇa. Kṛṣṇa says in Bhagavad Gītā, that of all letters, He is the letter ‘a’. Jīva Gosvāmī says that the way no vowel or consonant can be pronounced without ‘a’, nothing exists without Kṛṣṇa, i.e., Kṛṣṇa is the basis of everything. Without Kṛṣṇa, earth, water, air, moon, sun, etc., cannot exist.
Another meaning of Oṁ or auṁ is akārena ucyate Kṛṣṇa. Ukārena ucyate Rādhā; ‘u’ means ūrjaor śakti (energy). Kṛṣṇa’s śakti is Rādhā. Makārena iti jīva; ‘ṁ’ means jīvātmā. Therefore, auṁ means Rādhā, Kṛṣṇa, and Their devotees.
Devotees also chant the Gāyatrī mantra before worshiping the Deities in the temple. It is not required to chant the Gāyatrī mantra to worship the Deities as the Hare Kṛṣṇa mantra in itself is complete, but it is recommended in Deity worship and yajñas. Oṁ is also chanted during dīkṣā and marriage ceremonies. Devotees think about Rādhā, Kṛṣṇa, and Their devotees and ask Bhagavān to allow us to serve and give prem.
The Meaning of Tat
Tat means that or him; etat means this. Whatever one does, beginning with chanting Oṁ, one should offer the results to tat (Him). So by chanting Oṁ tat, one should think that he is working for Bhagavān and offer the fruits of his work to Him. One should not forget who he is working for and why he is working. Otherwise, one will think of something else and get entangled in reactions. Oṁtat helps us to remember this.
The Meaning of Sat
We desire sat (kriyante mokṣa-kāṅkṣibhiḥ). Sat means sad-bhāve sādhu-bhāve ca sad ity etat prayujyate. We want sat-bhāvana (good thoughts) and feelings of prem for Bhagavān (sādhu-bhāve). For this, we want to be in contact with Bhagavān, serve Him, and offer results to Him. Oṁ refers to sambandha, tat refers to abhidheya, sat refers to prayojana.
So whenever we start any activity, we chant Oṁ tat sat to remember that that activity is being done for Bhagavān and to offer results to Him and for attaining prem and sad-bhāvana.
We don’t have to chant oṁ tat sat but should understand the underlying concept. If we know this, there is no need to chant oṁ tat sat.
Because devotees dedicate their lives to Bhagavān and live and die for Bhagavān to attain prem, they don’t have to chant oṁ tat sat but should understand the underlying concept.Devotees don’t say oṁ tat sat but live oṁ tat sat.