CC Madhya 23.95-98
nīyamānā tu rasyatām
kāṣṭhām āpadyate parām
bhakti — by devotional service; nirdhūta-doṣāṇām — whose material contaminations are washed off; prasanna-ujjvala-cetasām — whose hearts are satisfied and clean; śrī-bhāgavata-raktānām — who are interested in understanding the transcendental meaning of Śrīmad-Bhāgavatam; rasika-āsaṅga-raṅgiṇām — who live with the devotees and enjoy their transcendental company; jīvanī-bhūta — has become the life; govinda-pāda — to the lotus feet of Govinda; bhakti-sukha-śriyām — those for whom the only opulence is the happiness of devotional service; prema-antaraṅga-bhūtāni — which are of a confidential nature in the loving affairs of the devotees and Kṛṣṇa; kṛtyāni — activities; eva — certainly; anutiṣṭhatām — of those performing; bhaktānām — of the devotees; hṛdi — in the hearts; rājantī — existing; saṁskāra-yugala — by both previous and current purificatory methods; ujjvalā — expanded; ratiḥ — love; ānanda-rūpā — whose form is transcendental bliss; eva — certainly; nīyamānā — being brought; tu — but; rasyatām — to tastefulness; kṛṣṇa-ādibhiḥ — by Kṛṣṇa and others; vibhāva-ādyaiḥ — by ingredients such as vibhāva; gataiḥ — gone; anubhava-adhvani — to the path of perception; prauḍha-ānandaḥ — mature bliss; camatkāra-kāṣṭhām — the platform of wonder; āpadyate — arrives at; parām — the supreme.
“ ‘For those who are completely washed of all material contamination by pure devotional service, who are always satisfied and brightly enlightened in the heart, who are always attached to understanding the transcendental meaning of Śrīmad-Bhāgavatam, who are always eager to associate with advanced devotees, whose happiness in the service of the lotus feet of Govinda is their very life, who always discharge the confidential activities of love — for such advanced devotees, who are by nature situated in bliss, the seed of love [rati] is expanded in the heart by previous and current reformatory processes. Thus the mixture of ecstatic ingredients becomes tasty and, being within the perception of the devotee, reaches the highest platform of wonder and deep bliss.’
These verses are found in the Bhakti-rasāmṛta-sindhu (2.1.7-10).