B.G 18.57

चेतसा सर्वकर्माणि मयि संन्यस्य मत्परः। बुदि्धयोगमुपाश्रित्य मच्चित्तः सततं भव ॥५७॥

cetasā sarvakarmāṇi mayi saṃnyasya matparaḥ। buddhi-yogam upāśritya mac-cittaḥ satataṃ bhava ॥57॥

[चेतसा (cetasā) - with the mind; सर्वकर्माणि (sarvakarmāṇi) - all actions; मयि (mayi) - in me; संन्यस्य (saṃnyasya) - renouncing; मत्परः (matparaḥ) - devoted to me; बुदि्धयोगम् (buddhi-yogam) - the yoga of wisdom; उपाश्रित्य (upāśritya) - taking refuge; मच्चित्तः (mac-cittaḥ) - with mind absorbed in me; सततं (satatam) - always; भव (bhava) - be;]

Renounce all actions in Me with your mind, be devoted to Me, take refuge in 'buddhi-yoga', i.e. the Yoga-of-wisdom, and always have your mind absorbed in Me.

Gīta Tātparya 18.57

This verse highlights the difference between someone who has taken refuge in the Lord and someone who is oriented in material actions based on the flowery language of the Vedas. 'He is indeed the supreme among all' - with that state of mind he is dedicatedly absorbed. In that state, the aspirant has complete control over the mental modifications.

भगवत्संश्रितस्य त्रैविद्यस्य च चेतसैव विशेष इत्याह - चेतसा सर्वकर्माणीति।

bhagavatsaṁśritasya traividyasya ca cetasaiva viśeṣa ityāha - cetasā sarvakarmāṇīti।

[भगवत्संश्रितस्य (bhagavatsaṁśritasya) - of one who has taken refuge in the Lord; त्रैविद्यस्य (traividyasya) - of the knower of the three Vedas / one who performs material oriented actions based on flowery language of the Vedas; च (ca) - and; चेतसा (cetasā) - by the mind; एव (eva) - indeed; विशेषः (viśeṣaḥ) - distinction; इति (iti) - thus; आह (āha) - says; चेतसा (cetasā) - by the mind; सर्वकर्माणि (sarvakarmāṇi) - all actions; इति (iti) - thus;]

The distinction for one who has taken refuge in the Lord and the one who is oriented in material actions based on the flowery language of the Vedas is brought out by the verse - 'cetasā sarvakarmāṇi', i.e. 'Renounce all actions in Me with your mind'.

स एव सर्वस्मात् परम इति भावोऽस्येति तत्परः। तत्र चित्तवृत्तिनिरोधोऽपि। बुदि्धयोगः प्रत्याहारादिः ॥५७॥

sa eva sarvasmāt parama iti bhāvo'syeti tatparaḥ। tatra cittavṛttinirodho'pi। buddhi-yogaḥ pratyāhārādiḥ ॥57॥

[स (sa) - he; एव (eva) - indeed; सर्वस्मात् (sarvasmāt) - from all; परम (parama) - supreme; इति (iti) - thus; भावः (bhāvaḥ) - state; अस्य (asya) - of him; इति (iti) - thus; तत्परः (tatparaḥ) - dedicatedly absorbed; तत्र (tatra) - there; चित्तवृत्तिनिरोधः (cittavṛttinirodhaḥ) - control of mental modifications; अपि (api) - also; बुदि्धयोगः (buddhi-yogaḥ) - intellect yoga; प्रत्याहारादिः (pratyāhārādiḥ) - withdrawal and others;]

'He is indeed the supreme among all' - with that state of mind he is dedicatedly absorbed. In that state, the aspirant has complete control over the mental modifications. The term 'buddhi-yoga', i.e. the Yoga-of-wisdom, in the context refers to withdrawal and other practices as explained earlier.