dhanyasyāyaṁ navaḥ premā
yasyonmīlati cetasi
antar-vāṇībhir apy asya
mudrā suṣṭhu su-durgamā
dhanyasya - of a most fortunate person; ayam - this; navaḥ - new; premā - love of Godhead; yasya - of whom; unmīlati - manifests; cetasi - in the heart; antaḥ-vāṇībhiḥ - by persons well versed in the śāstras; api - even; asya - of him; mudrā - the symptoms; suṣṭhu - exceedingly; su-durgamā - difficult to understand.
This verse is quoted from the Bhakti-rasāmṛta-sindhu (1.4.17).