SB 4.8.20
yasyanghri-padmam paricarya visva-
vibhavanayatta-gunabhipatteh
ajo ’dhyatisthat khalu paramesthyam
padam jitatma-svasanabhivandyam
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Suniti continued: The Supreme Personality of Godhead is so great that simply by worshiping His lotus feet, your great-grandfather, Lord Brahma, acquired the necessary qualifications to create this universe. Although he is unborn and is the chief of all living creatures, he is situated in that exalted post because of the mercy of the Supreme Personality of Godhead, whom even great yogis worship by controlling the mind and regulating the life air [prana].
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
Suniti cited the example of Lord Brahma, who was Dhruva Maharaja’s great-grandfather. Although Lord Brahma is also a living being, by his penance and austerity he acquired the exalted position of creator of this universe by the mercy of the Supreme Lord. To become successful in any attempt, one not only has to undergo severe penances and austerities, but also must be dependent on the mercy of the Supreme Personality of Godhead. This indication had been given to Dhruva Maharaja by his stepmother and was now confirmed by his own mother, Suniti.