Srimad Bhagavatam Canto 04, Chapter 12, Text 42

SB 4.12.42

yah pañca-varso guru-dara-vak-sarair
bhinnena yato hrdayena duyata
vanam mad-adesa-karo ’jitam prabhum
jigaya tad-bhakta-gunaih parajitam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The great sage Narada continued: Just see how Dhruva Maharaja, aggrieved at the harsh words of his stepmother, went to the forest at the age of only five years and under my direction underwent austerity. Although the Supreme Personality of Godhead is unconquerable, Dhruva Maharaja defeated Him with the specific qualifications possessed by the Lord’s devotees.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada: 
The Supreme Godhead is unconquerable; no one can conquer the Lord. But He voluntarily accepts subordination to the devotional qualities of His devotees. For example, Lord Krsna accepted subordination to the control of mother Yasoda because she was a great devotee. The Lord likes to be under the control of His devotees. In the Caitanya-caritamrta it is said that everyone comes before the Lord and offers Him exalted prayers, but the Lord does not feel as pleased when offered such prayers as He does when a devotee, out of pure love, chastises Him as a subordinate. The Lord forgets His exalted position and willingly submits to His pure devotee. Dhruva Maharaja conquered the Supreme Lord because at a very tender age, only five years old, he underwent all the austerities of devotional service. This devotional service was of course executed under the direction of a great sage, Narada. This is the first principle of devotional service — adau gurv-asrayam. In the beginning one must accept a bona fide spiritual master, and if a devotee follows strictly the direction of the spiritual master, as Dhruva Maharaja followed the instruction of Narada Muni, then it is not difficult for him to achieve the favor of the Lord.
The sum total of devotional qualities is development of unalloyed love for Krsna. This unalloyed love for Krsna can be achieved simply by hearing about Krsna. Lord Caitanya accepted this principle — that if one in any position submissively hears the transcendental message spoken by Krsna or about Krsna, then gradually he develops the quality of unalloyed love, and by that love only he can conquer the unconquerable. The Mayavadi philosophers aspire to become one with the Supreme Lord, but a devotee surpasses that position. Not only does a devotee become one in quality with the Supreme Lord, but he sometimes becomes the father, mother or master of the Lord. Arjuna also, by his devotional service, made Lord Krsna his chariot driver; he ordered the Lord, “Put my chariot here,” and the Lord executed his order. These are some examples of how a devotee can acquire the exalted position of conquering the unconquerable.
Srimad Bhagavatam Canto 04, Chapter 12, Text 41
Srimad Bhagavatam Canto 04, Chapter 12, Text 43