SB 3.8.21

ततो निवृत्तोऽप्रतिलब्धकामः स्वधिष्ण्यमासाद्य पुनः स देवः ।
शनैर्जितश्वासनिवृत्तचित्तो न्यषीददारूढसमाधियोगः ॥२१॥

tato nivṛtto 'pratilabdha-kāmaḥ
sva-dhiṣṇyam āsādya punaḥ sa devaḥ
śanair jita-śvāsa-nivṛtta-citto
nyaṣīdad ārūḍha-samādhi-yogaḥ

tataḥ—thereafter; nivṛttaḥ—retired from that endeavor; apratilabdha-kāmaḥ—without achievement of the desired destination; sva-dhiṣṇyam—own seat; āsādya—reaching; punaḥ—again; saḥ—he; devaḥ—the demigod; śanaiḥ—without delay; jita-śvāsa—controlling the breathing; nivṛtta—retired; cittaḥ—intelligence; nyaṣīdat—sat down; ārūḍha—in confidence; samādhi-yogaḥ—in meditation on the Lord.

Thereafter, being unable to achieve the desired destination, he retired from such searching and came back again to the top of the lotus. Thus, controlling all objectives, he concentrated his mind on the Supreme Lord.

Samādhi involves concentrating the mind upon the supreme cause of all, even if one is unaware of whether His actual nature is personal, impersonal or localized. Concentration of the mind on the Supreme is certainly a form of devotional service. To cease from personal sense endeavors and to concentrate on the supreme cause is a sign of self-surrender, and when self-surrender is present, that is a sure sign of devotional service. Each and every living entity needs to engage in devotional service to the Lord if he wishes to understand the ultimate cause of his existence.