B.G 3.30

मयि सर्वाणि कर्माणि संन्यस्याध्यात्मचेतसा। निराशीर्निर्ममो भूत्वा युद्ध्यस्व विगतज्वरः ॥३०॥

mayi sarvāṇi karmāṇi saṁnyasyādhyātmacētasā। nirāśīrnirmamō bhūtvā yuddhyasva vigatajvaraḥ ॥30॥

[मयि सर्वाणि कर्माणि संन्यस्य आध्यात्म चेतसा। निराशीः निर्ममो भूत्वा युद्ध्यस्व विगत ज्वरः॥
mayi = in me; sarvāṇi = all; karmāṇi = actions and duties; saṁnyasya = renouning / dedicating; ādhyātma cētasā = having the right understanding of 'atyman' i.e. the lord is the doer and not me; nirāśīḥ = without selfish desire; nirmamō = without the notion that I am the doer; bhūtvā = becoming; yuddhyasva = engage in battle; vigata = devoid of; jvaraḥ = fever / fear;]

Having no selfish desire, having no notion of agency, dedicating all actions to Me become 'ādhyātma cētasā', i.e. one who understands lord only as the doer and surrenders the self to Bhagavan. With this understanding, engage in the battle with no fear.

Gīta Bhāshya 3.30

'saṁnyāsa' - having the understanding that the lord (Bhagavan) only acts. 'ādhyātma cētasā' - one who surrenders his 'atman' to Bhagavan. 'nirmama' - having the understanding that I am not the doer.

अतः सर्वाणि कर्माणि मय्येव संन्यस्य, भ्रान्त्या जीवे अध्यारोपितानि मय्येव विसृत्य, भगवानेव सर्वाणि कर्माणि करोतीति मत्पूजेति च। आत्मानं माम् अधिकृत्य यच्चेतः तत् अध्यात्मचेतः। संन्यासस्तु भगवान् करोतीति। निर्ममत्वं नाहं करोमीति ॥३०॥

ataḥ sarvāṇi karmāṇi mayyēva saṁnyasya bhrāntyā jīvē adhyārōpitāni mayyēva visr̥tya, bhagavānēva sarvāṇi karmāṇi karōtīti matpūjēti ca। ātmānaṁ mām adhikr̥tya yaccētaḥ tat adhyātmacētaḥ। saṁnyāsastu bhagavān karōtīti। nirmamatvaṁ nāhaṁ karōmīti ॥30॥

[ataḥ = therefore; sarvāṇi = all; karmāṇi = actions; mayyēva = in me only; saṁnyasya = renouncing; bhrāntyā = due to delusion; jīvē = the individual soul; adhyārōpitāni = superimposed; mayyēva = in me only; visr̥tya = having abandoned; bhagavānēva = in the lord only; sarvāṇi = all; karmāṇi = actions; karōtīti = performs; matpūjēti worships me; ca = and/even;। ātmānaṁ = the 'ātman'; 'mām = is Me; adhikr̥tya = having subdued; yaccētaḥ = one who; tat = that; adhyātmacētaḥ = is 'adhyātmacētaḥ';। saṁnyāsastu = 'saṁnyāsa' in this context means; bhagavān = the lord; karōtīti = onely acts;। nirmamatvaṁ = 'nirmama' is having the understanding; nāhaṁ = I am not; karōmīti = the doer;]

Therefore, renounce all actions in Me only, i.e. having abandoned the superimposed notion that I am the doer arising due to delusion, having understood the lord (Bhagavan) as the real doer of all actions, worship Me. The one who surrenders his 'atman' to Me is the 'ādhyātma cētasā'. 'saṁnyāsa' in this context means having the understanding that the lord (Bhagavan) only acts. 'nirmama' mans having the understanding that I am not the doer