samyaṅ-masṛṇita-svānto
samyaṅ-masṛṇita-svānto mamatvātiśayāṅkitaḥ |
bhāvaḥ sa eva sāndrātmā budhaiḥ premā nigadyate ||
(Bhakti-rasāmṛta-sindhu: 1.4.1)
“That particular bhāva, intense in nature, because of which the heart is completely melted, and [thus] marked by a profusion of my-ness (mamatva) [i.e., loving attachment to Kṛṣṇa], is called prema by the wise.”