Although Dhruva Mahārāja was a small boy, he wanted to offer prayers to the Supreme Personality of Godhead in suitable language. But because he was inexperienced, he could not adjust himself immediately. The Supreme Personality of Godhead, being situated in everyone’s heart, could understand Dhruva Mahārāja’s awkward position. Out of His causeless mercy He touched His conchshell to the forehead of Dhruva Mahārāja, who stood before Him with folded hands.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
स तं विवक्षन्तमतद्विदं हरिः ज्ञात्वास्य सर्वस्य च हृद्यवस्थितः । कृताञ्जलिं ब्रह्ममयेन कम्बुना पस्पर्श बालं कृपया कपोले
sa taṃ vivakṣantamatadvidaṃ hariḥ jñātvāsya sarvasya ca hṛdyavasthitaḥ | kṛtāñjaliṃ brahmamayena kambunā pasparśa bālaṃ kṛpayā kapole
SB 4.9.4