SB 7.5.21

आरोप्याङ्कमवघ्राय मूर्धन्यश्रुकलाम्बुभिः ।
आसिञ्चन् विकसद्वक्त्रमिदमाह युधिष्ठिर ॥२१॥

āropyāṅkam avaghrāya
mūrdhany aśru-kalāmbubhiḥ
āsiñcan vikasad-vaktram
idam āha yudhiṣṭhira

āropya - placing; aṅkam - on the lap; avaghrāya mūrdhani - smelling his head; aśru - of tears; kalā-ambubhiḥ - with water from drops; āsiñcan - moistening; vikasat-vaktram - his smiling face; idam - this; āha - said; yudhiṣṭhira - O Mahārāja Yudhiṣṭhira.

Text

Nārada Muni continued: My dear King Yudhiṣṭhira, Hiraṇyakaśipu seated Prahlāda Mahārāja on his lap and began smelling his head. With affectionate tears gliding down from his eyes and moistening the child’s smiling face, he spoke to his son as follows.

Purport

If a child or disciple falls at the feet of the father or spiritual master, the superior responds by smelling the head of the subordinate.

Srimad Bhagavatam. Canto 7: The Science of God

Chapter 5: Prahlada Maharaja, the Saintly Son of Hiranyakasipu. Text 21

Nārada Muni continued: My dear King Yudhiṣṭhira, Hiraṇyakaśipu seated Prahlāda Mahārāja on his lap and began smelling his head. With affectionate tears gliding down from his eyes and moistening the child’s smiling face, he spoke to his son as follows.