Caitanya-caritāmṛta 9.256
ācārya kahe, — ‘varṇāśrama-dharma, kṛṣṇe samarpaṇa’ ei haya kṛṣṇa-bhaktera śreṣṭha ‘sādhana’
[aachaarya kahe, — ‘varnaashrama-dharma, krishne samarpana’ ei haya krishna-bhaktera shreshtha ‘saadhana’]
Blended reading (Sanskrit + English inline)
ācārya kahe, — ‘varṇāśrama-dharma, kṛṣṇe samarpaṇa’ ei haya kṛṣṇa-bhaktera śreṣṭha ‘sādhana’
The ācārya replied, “When the activities of the four castes and the four āśramas are dedicated to Kṛṣṇa, they constitute the best means whereby one can attain the highest goal of life.
My note
Source: vedabase.io