Srimad-Bhagavatam: Canto 8 - Chapter 1 - Verse 2-3
चिन्तयन्त्येकया बुद्ध्या महापुरुषमीश्वरम् ।प्रगृह्येन्द्रियदुष्टाश्वान्मनसा बुद्धिसारथि: ॥ २ ॥मनश्चैकाग्रया बुद्ध्या भगवत्यखिलात्मनि ।वासुदेवे समाधाय चचार ह पयोव्रतम् ॥ ३ ॥
cintayanty ekayā buddhyāmahā-puruṣam īśvarampragṛhyendriya-duṣṭāśvānmanasā buddhi-sārathiḥ
With full, undiverted attention, Aditi thought of the Supreme Personality of Godhead and in this way brought under full control her mind and senses, which resembled forceful horses. She concentrated her mind upon the Supreme Lord, Vāsudeva. Thus she performed the ritualistic ceremony known as payo-vrata.
This is the process of bhakti-yoga. “One should render transcendental loving service to the Supreme Lord Kṛṣṇa favorably and without desire for material profit or gain through fruitive activities or philosophical speculation. That is called pure devotional service.” One simply has to concentrate upon the lotus feet of Vāsudeva, Kṛṣṇa (sa vai manaḥ kṛṣṇa-padāravindayoḥ). Then the mind and senses will be controlled, and one can engage himself fully in the devotional service of the Lord. The devotee does not need to practice the haṭha-yoga system to control the mind and senses; his mind and senses are automatically controlled because of unalloyed devotional service to the Lord.