CC Madhya 23.7
bhāvaḥ sa eva sāndrātmā
budhaiḥ premā nigadyate
samyak — completely; masṛṇita-sva-antaḥ — which makes the heart soft; mamatva — of a sense of ownership; atiśaya-aṅkitaḥ — marked with an abundance; bhāvaḥ — emotion; saḥ — that; eva — certainly; sāndra-ātmā — whose nature is very condensed; budhaiḥ — by learned persons; premā — love of Godhead; nigadyate — is described.
“ ‘When that bhāva softens the heart completely, becomes endowed with a great feeling of possessiveness in relation to the Lord and becomes very much condensed and intensified, it is called prema [love of Godhead] by learned scholars.
This verse is also found in the Bhakti-rasāmṛta-sindhu (1.4.1).