B.G 17.27 and 28

yajñe tapasi dāne ca sthitiḥ saditi cocyate। karma caiva tadarthīyaṃ sadityevābhidhīyate ॥27॥

Steadiness in sacrifice, austerity, and charity is referred to as 'sat', i.e. real, and so also is the action taken for that purpose.

aśraddhayā hutaṃ dattaṃ tapastaptaṃ kṛtaṃ ca yat। asadityucyate pārtha na ca tat pretya no iha ॥28॥

O son of Pritha, whatever is offered, given, or performed without faith is considered 'asat', i.e. unreal. It benefits us neither in this life nor in the afterlife.

Gīta Tātparya 17.27 and 28

The sound 'Om tat sat' is renowned as the name of Lord Vishnu. A mantra recited without understanding its meaning is ineffective and serves only to protect one's ego. Therefore, the true meaning of the mantra should be understood. For the purpose of attaining the fruits of sāttvika actions, one must act with devotion and remembrance of the divine. The sentiment is - anything other than the truth is false.

tatsambandhitvādeva karmādi sat। oṃ tatsaditi nāmnāṃ viṣṇauḥ prasiddhatvāt।

Because of its connection with THAT, actions and such austerities are called 'sat', i.e. real. The sound 'Om tat sat' is thus renowned as the name of Lord Vishnu.

"sravatyanoṅkṛtaṃ brahma parastācca viśīryate। ano'ṅkr̥taṁ āsuraṁ karma"

"The breath marked with Om, flows beyond and disintegrates into Brahman. The unmarked breath is considered a demonic action."

iti śruteḥ anoṅkṛtasya āsuratvaprasiddheḥ।

Thus, it is known from the scriptures about the fame of demon hood of the unmarked.

anarthajñodito mantro nirarthastrāti mānataḥ। yanmantrastena kathito mantrārtho jñeya eva tat॥

"A mantra recited without understanding its meaning is ineffective and only serves to protect one's ego. Therefore, the true meaning of the mantra should be understood."

iti paiṅgiśruteśca।

- stated thus in the Paiṅgi Vedic testimonial.

tadarthatvena phalānabhisandhipūrvakakarmaṇa eva sāttvikatvācca। tadbhaktyā tatsmaraṇapūrvakameva sadanyadasadeveti bhāvaḥ। rājasasyāpi asadantarbhāva eva। viṣṇuśraddhārahitatvāt॥

For the purpose of attaining the fruits of actions, which are sāttvika, one must act with devotion and remembrance of the divine. The sentiment is that anything other than the truth is false. Even those with a rājasa nature include falsehood due to a lack of faith in Viṣṇu.

"sāttvikaṃ mokṣadaṃ karma rājasaṃ sṛtiduḥkhadam। tāmasaṃ pātadaṃ jñeyaṃ tatkuryāt karma vaiṣṇavam॥"

"Actions performed in the mode of goodness lead to liberation, those in the mode of passion lead to sorrow in the cycle of birth and death, and those in the mode of ignorance lead to downfall. Therefore, one should perform actions that are related to Vishnu."

ityāgneyē॥

- stated thus in the Agni Purana.

॥ iti śrīmadānandatīrthabhagavatpādācāryaviracite śrībhagavadgītātātparyanirṇaye saptadaśādhyāyaḥ ॥

Thus ends the seventeenth chapter of the Śrī Bhagavad Gītā purport, composed by Ānandatīrtha Bhagavatpāda Ācārya.

॥ oṁ tatsaditi śrīmadbhagavadgītāsu upaniṣatsu brahmavidyāyāṁ yogaśāstre śrīkṛṣṇārjunasaṁvāde śraddhātrayavibhāgayogo nāma saptadaśādhyāyaḥ ॥

'Om Tat Sat'. Thus, the seventeenth chapter of the Bhagavad Gita, named 'The Yoga of the Division of the Threefold Faith', is declared in the Upanishads, in the knowledge of Brahman, and in the science of Yoga, through the dialogue between Sri Krishna and Arjuna ends.